Lint Report

Overview

	Correctness
8	DefaultLocale: Implied default locale in case conversion
1	OldTargetApi: Target SDK attribute is not targeting latest version
1	SimpleDateFormat: Implied locale in date format
1	GradleDependency: Obsolete Gradle Dependency
	Disabled Checks (29)

Implied default locale in case conversion

../../src/main/java/h/com/serialportapi/util/ByteUtil.java:39: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

  36             buffer[1] = Character.forDigit(src[i] & 0x0F, 16);
  37             builder.append(buffer);
  38         }
  39         return builder.toString().toUpperCase();                                                    
  40     }
  41 
  42     /**

../../src/main/java/h/com/serialportapi/util/ByteUtil.java:73: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

  70      * @return
  71      */
  72     public static String decimal2fitHex(long num) {
  73         String hex = Long.toHexString(num).toUpperCase();                                           
  74         if (hex.length() % 2 != 0) {
  75             return "0" + hex;
  76         }

../../src/main/java/h/com/serialportapi/util/ByteUtil.java:77: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

  74         if (hex.length() % 2 != 0) {
  75             return "0" + hex;
  76         }
  77         return hex.toUpperCase();                                                                   
  78     }
  79 
  80     /**

../../src/main/java/h/com/serialportapi/util/ByteUtil.java:139: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

 136     public static byte[] hexStr2bytes(String hex) {
 137         int len = (hex.length() / 2);
 138         byte[] result = new byte[len];
 139         char[] achar = hex.toUpperCase().toCharArray();                                             
 140         for (int i = 0; i < len; i++) {
 141             int pos = i * 2;
 142             result[i] = (byte) (hexChar2byte(achar[pos]) << 4 | hexChar2byte(achar[pos + 1]));

../../src/main/java/h/com/serialportapi/comn/CommPacket.java:829: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

 826         } else {
 827             //return String.valueOf((sendData.length() / 2) + 1);
 828             if (Integer.toHexString((sendData.length() / 2) + 1).length() == 1) {
 829                 return "0" + Integer.toHexString((sendData.length() / 2)).toUpperCase();            
 830             } else {
 831                 return Integer.toHexString((sendData.length() / 2)).toUpperCase();
 832             }

../../src/main/java/h/com/serialportapi/comn/CommPacket.java:831: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

 828             if (Integer.toHexString((sendData.length() / 2) + 1).length() == 1) {
 829                 return "0" + Integer.toHexString((sendData.length() / 2)).toUpperCase();
 830             } else {
 831                 return Integer.toHexString((sendData.length() / 2)).toUpperCase();                  
 832             }
 833         }
 834     }

../../src/main/java/h/com/serialportapi/comn/Packet.java:76: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

 73             if (hex.length() == 1) {
 74                 hex = '0' + hex;
 75             }
 76             ret += " 0x" + hex.toUpperCase();                                                       
 77         }
 78         return ret;
 79     }

../../src/main/java/h/com/serialportapi/comn/SerialReadThread.java:298: Implicitly using the default locale is a common source of bugs: Use toUpperCase(Locale) instead. For strings meant to be internal use Locale.ROOT, otherwise Locale.getDefault().

 295         if (hex.length() == 1) {
 296             hex = "0" + hex;
 297         }
 298         return hex.toUpperCase();                                                                   
 299     }
 300 
 301     private void postMessage(String hexStr) {

Calling String#toLowerCase() or #toUpperCase() without specifying an explicit locale is a common source of bugs. The reason for that is that those methods will use the current locale on the user's device, and even though the code appears to work correctly when you are developing the app, it will fail in some locales. For example, in the Turkish locale, the uppercase replacement for i is not I.

If you want the methods to just perform ASCII replacement, for example to convert an enum name, call String#toUpperCase(Locale.US) instead. If you really want to use the current locale, call String#toUpperCase(Locale.getDefault()) instead.

More info: http://developer.android.com/reference/java/util/Locale.html#default_locale

To suppress this error, use the issue id "DefaultLocale" as explained in the Suppressing Warnings and Errors section.

DefaultLocale Correctness Warning Priority 6/10

Target SDK attribute is not targeting latest version

../../build.gradle:7: Not targeting the latest versions of Android; compatibility modes apply. Consider testing and updating this version. Consult the android.os.Build.VERSION_CODES javadoc for details.

  4     compileSdkVersion 26
  5     defaultConfig {
  6         minSdkVersion 19
  7         targetSdkVersion 26
                                                                        
  8         versionCode 1
  9         versionName "1.0"
 10

When your application runs on a version of Android that is more recent than your targetSdkVersion specifies that it has been tested with, various compatibility modes kick in. This ensures that your application continues to work, but it may look out of place. For example, if the targetSdkVersion is less than 14, your app may get an option button in the UI.

To fix this issue, set the targetSdkVersion to the highest available value. Then test your app to make sure everything works correctly. You may want to consult the compatibility notes to see what changes apply to each version you are adding support for: http://developer.android.com/reference/android/os/Build.VERSION_CODES.html as well as follow this guide:
https://developer.android.com/distribute/best-practices/develop/target-sdk.html

More info:

Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "OldTargetApi" as explained in the Suppressing Warnings and Errors section.

OldTargetApi Correctness Warning Priority 6/10

Implied locale in date format

../../src/main/java/h/com/serialportapi/util/TimeUtil.java:13: To get local formatting use getDateInstance(), getDateTimeInstance(), or getTimeInstance(), or use new SimpleDateFormat(String template, Locale locale) with for example Locale.US for ASCII dates.

 10 public class TimeUtil {
 11 
 12     public static final SimpleDateFormat DEFAULT_FORMAT =
 13         new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");                                            
 14 
 15     public static String currentTime() {
 16         Date date = new Date();

Almost all callers should use getDateInstance(), getDateTimeInstance(), or getTimeInstance() to get a ready-made instance of SimpleDateFormat suitable for the user's locale. The main reason you'd create an instance this class directly is because you need to format/parse a specific machine-readable format, in which case you almost certainly want to explicitly ask for US to ensure that you get ASCII digits (rather than, say, Arabic digits).

Therefore, you should either use the form of the SimpleDateFormat constructor where you pass in an explicit locale, such as Locale.US, or use one of the get instance methods, or suppress this error if really know what you are doing.

More info: http://developer.android.com/reference/java/text/SimpleDateFormat.html

To suppress this error, use the issue id "SimpleDateFormat" as explained in the Suppressing Warnings and Errors section.

SimpleDateFormat Correctness Warning Priority 6/10

Obsolete Gradle Dependency

../../build.gradle:50: A newer version of io.reactivex.rxjava2:rxjava than 2.1.8 is available: 2.1.9

 47     // 串口

 48     implementation 'com.github.licheedev.Android-SerialPort-API:serialport:1.0.1'
 49     //rx

 50     implementation 'io.reactivex.rxjava2:rxjava:2.1.8'
                                             
 51     implementation 'io.reactivex.rxjava2:rxandroid:2.0.2'
 52     // eventbus

 53     implementation 'org.greenrobot:eventbus:3.1.1'

GradleDependency Correctness Warning Priority 4/10

Disabled Checks

One or more issues were not run by lint, either because the check is not enabled by default, or because it was disabled with a command line flag or via one or more lint.xml configuration files in the project directories.

AppLinksAutoVerifyError

Disabled By: Default

Ensures that app links are correctly set and associated with website.

More info: https://g.co/appindexing/applinks

To suppress this error, use the issue id "AppLinksAutoVerifyError" as explained in the Suppressing Warnings and Errors section.

AppLinksAutoVerifyWarning

Disabled By: Default

Ensures that app links are correctly set and associated with website.

More info: https://g.co/appindexing/applinks

To suppress this error, use the issue id "AppLinksAutoVerifyWarning" as explained in the Suppressing Warnings and Errors section.

BackButton

Disabled By: Default

According to the Android Design Guide,

"Other platforms use an explicit back button with label to allow the user to navigate up the application's hierarchy. Instead, Android uses the main action bar's app icon for hierarchical navigation and the navigation bar's back button for temporal navigation."
This check is not very sophisticated (it just looks for buttons with the label "Back"), so it is disabled by default to not trigger on common scenarios like pairs of Back/Next buttons to paginate through screens.

More info: http://developer.android.com/design/patterns/pure-android.html

To suppress this error, use the issue id "BackButton" as explained in the Suppressing Warnings and Errors section.

ConvertToWebp

Disabled By: Default

The WebP format is typically more compact than PNG and JPEG. As of Android 4.2.1 it supports transparency and lossless conversion as well. Note that there is a quickfix in the IDE which lets you perform conversion.

Launcher icons must be in the PNG format.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "ConvertToWebp" as explained in the Suppressing Warnings and Errors section.

EasterEgg

Disabled By: Default

An "easter egg" is code deliberately hidden in the code, both from potential users and even from other developers. This lint check looks for code which looks like it may be hidden from sight.
To suppress this error, use the issue id "EasterEgg" as explained in the Suppressing Warnings and Errors section.

FieldGetter

Disabled By: Default

Accessing a field within the class that defines a getter for that field is at least 3 times faster than calling the getter. For simple getters that do nothing other than return the field, you might want to just reference the local field directly instead.

NOTE: As of Android 2.3 (Gingerbread), this optimization is performed automatically by Dalvik, so there is no need to change your code; this is only relevant if you are targeting older versions of Android.

More info: http://developer.android.com/guide/practices/design/performance.html#internal_get_set

To suppress this error, use the issue id "FieldGetter" as explained in the Suppressing Warnings and Errors section.

GoogleAppIndexingApiWarning

Disabled By: Default

Adds URLs to get your app into the Google index, to get installs and traffic to your app from Google Search.

More info: https://g.co/AppIndexing/AndroidStudio

Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "GoogleAppIndexingApiWarning" as explained in the Suppressing Warnings and Errors section.

IconExpectedSize

Disabled By: Default

There are predefined sizes (for each density) for launcher icons. You should follow these conventions to make sure your icons fit in with the overall look of the platform.

More info: http://developer.android.com/design/style/iconography.html

To suppress this error, use the issue id "IconExpectedSize" as explained in the Suppressing Warnings and Errors section.

KotlinPropertyAccess

Disabled By: Default

For a method to be represented as a property in Kotlin, strict “bean”-style prefixing must be used.

Accessor methods require a ‘get’ prefix or for boolean-returning methods an ‘is’ prefix can be used.

More info: https://android.github.io/kotlin-guides/interop.html#property-prefixes

To suppress this error, use the issue id "KotlinPropertyAccess" as explained in the Suppressing Warnings and Errors section.

LambdaLast

Disabled By: Default

To improve calling this code from Kotlin,
parameter types eligible for SAM conversion should be last.

More info: https://android.github.io/kotlin-guides/interop.html#lambda-parameters-last

To suppress this error, use the issue id "LambdaLast" as explained in the Suppressing Warnings and Errors section.

LogConditional

Disabled By: Default

The BuildConfig class (available in Tools 17) provides a constant, "DEBUG", which indicates whether the code is being built in release mode or in debug mode. In release mode, you typically want to strip out all the logging calls. Since the compiler will automatically remove all code which is inside a "if (false)" check, surrounding your logging calls with a check for BuildConfig.DEBUG is a good idea.

If you really intend for the logging to be present in release mode, you can suppress this warning with a @SuppressLint annotation for the intentional logging calls.
To suppress this error, use the issue id "LogConditional" as explained in the Suppressing Warnings and Errors section.

MangledCRLF

Disabled By: Default

On Windows, line endings are typically recorded as carriage return plus newline: \r\n.

This detector looks for invalid line endings with repeated carriage return characters (without newlines). Previous versions of the ADT plugin could accidentally introduce these into the file, and when editing the file, the editor could produce confusing visual artifacts.

More info: https://bugs.eclipse.org/bugs/show_bug.cgi?id=375421

To suppress this error, use the issue id "MangledCRLF" as explained in the Suppressing Warnings and Errors section.

MinSdkTooLow

Disabled By: Default

The value of the minSdkVersion property is too low and can be incremented without noticeably reducing the number of supported devices.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "MinSdkTooLow" as explained in the Suppressing Warnings and Errors section.

MissingRegistered

Disabled By: Default

If a class is referenced in the manifest or in a layout file, it must also exist in the project (or in one of the libraries included by the project. This check helps uncover typos in registration names, or attempts to rename or move classes without updating the manifest file properly.

More info: http://developer.android.com/guide/topics/manifest/manifest-intro.html

To suppress this error, use the issue id "MissingRegistered" as explained in the Suppressing Warnings and Errors section.

NegativeMargin

Disabled By: Default

Margin values should be positive. Negative values are generally a sign that you are making assumptions about views surrounding the current one, or may be tempted to turn off child clipping to allow a view to escape its parent. Turning off child clipping to do this not only leads to poor graphical performance, it also results in wrong touch event handling since touch events are based strictly on a chain of parent-rect hit tests. Finally, making assumptions about the size of strings can lead to localization problems.
To suppress this error, use the issue id "NegativeMargin" as explained in the Suppressing Warnings and Errors section.

NewerVersionAvailable

Disabled By: Default

This detector checks with a central repository to see if there are newer versions available for the dependencies used by this project. This is similar to the GradleDependency check, which checks for newer versions available in the Android SDK tools and libraries, but this works with any MavenCentral dependency, and connects to the library every time, which makes it more flexible but also much slower.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "NewerVersionAvailable" as explained in the Suppressing Warnings and Errors section.

NoHardKeywords

Disabled By: Default

Do not use Kotlin’s hard keywords as the name of methods or fields.
These require the use of backticks to escape when calling from Kotlin.
Soft keywords, modifier keywords, and special identifiers are allowed.

For example, Mockito’s when function requires backticks when used from Kotlin:

val callable = Mockito.mock(Callable::class.java)
Mockito.`when`(callable.call()).thenReturn(/* … */)

More info: https://android.github.io/kotlin-guides/interop.html#no-hard-keywords

To suppress this error, use the issue id "NoHardKeywords" as explained in the Suppressing Warnings and Errors section.

PermissionImpliesUnsupportedChromeOsHardware

Disabled By: Default

The <uses-permission> element should not require a permission that implies an unsupported Chrome OS hardware feature. Google Play assumes that certain hardware related permissions indicate that the underlying hardware features are required by default. To fix the issue, consider declaring the corresponding uses-feature element with required="false" attribute.

More info: https://developer.android.com/topic/arc/manifest.html#implied-features

Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "PermissionImpliesUnsupportedChromeOsHardware" as explained in the Suppressing Warnings and Errors section.

Registered

Disabled By: Default

Activities, services and content providers should be registered in the AndroidManifest.xml file using <activity>, <service> and <provider> tags.

If your activity is simply a parent class intended to be subclassed by other "real" activities, make it an abstract class.

More info: http://developer.android.com/guide/topics/manifest/manifest-intro.html

To suppress this error, use the issue id "Registered" as explained in the Suppressing Warnings and Errors section.

RequiredSize

Disabled By: Default

All views must specify an explicit layout_width and layout_height attribute. There is a runtime check for this, so if you fail to specify a size, an exception is thrown at runtime.

It's possible to specify these widths via styles as well. GridLayout, as a special case, does not require you to specify a size.
To suppress this error, use the issue id "RequiredSize" as explained in the Suppressing Warnings and Errors section.

SelectableText

Disabled By: Default

If a <TextView> is used to display data, the user might want to copy that data and paste it elsewhere. To allow this, the <TextView> should specify android:textIsSelectable="true".

This lint check looks for TextViews which are likely to be displaying data: views whose text is set dynamically. This value will be ignored on platforms older than API 11, so it is okay to set it regardless of your minSdkVersion.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "SelectableText" as explained in the Suppressing Warnings and Errors section.

StopShip

Disabled By: Default

Using the comment // STOPSHIP can be used to flag code that is incomplete but checked in. This comment marker can be used to indicate that the code should not be shipped until the issue is addressed, and lint will look for these. In Gradle projects, this is only checked for non-debug (release) builds.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "StopShip" as explained in the Suppressing Warnings and Errors section.

SyntheticAccessor

Disabled By: Default

A private inner class which is accessed from the outer class will force the compiler to insert a synthetic accessor; this means that you are causing extra overhead. This is not important in small projects, but is important for large apps running up against the 64K method handle limit, and especially for libraries where you want to make sure your library is as small as possible for the cases where your library is used in an app running up against the 64K limit.
To suppress this error, use the issue id "SyntheticAccessor" as explained in the Suppressing Warnings and Errors section.

TypographyQuotes

Disabled By: Default

Straight single quotes and double quotes, when used as a pair, can be replaced by "curvy quotes" (or directional quotes). This can make the text more readable.

Note that you should never use grave accents and apostrophes to quote, `like this'.

(Also note that you should not use curvy quotes for code fragments.)

More info: http://en.wikipedia.org/wiki/Quotation_mark

Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "TypographyQuotes" as explained in the Suppressing Warnings and Errors section.

UnknownNullness

Disabled By: Default

To improve referencing this code from Kotlin, consider adding
explicit nullness information here with either @NonNull or @Nullable.

More info: https://android.github.io/kotlin-guides/interop.html#nullability-annotations

To suppress this error, use the issue id "UnknownNullness" as explained in the Suppressing Warnings and Errors section.

UnpackedNativeCode

Disabled By: Default

This app loads native libraries using System.loadLibrary().

Consider adding android:extractNativeLibs="false" to the <application> tag in AndroidManifest.xml. Starting with Android 6.0, this will make installation faster, the app will take up less space on the device and updates will have smaller download sizes.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "UnpackedNativeCode" as explained in the Suppressing Warnings and Errors section.

UnsupportedChromeOsHardware

Disabled By: Default

The <uses-feature> element should not require this unsupported Chrome OS hardware feature. Any uses-feature not explicitly marked with required="false" is necessary on the device to be installed on. Ensure that any features that might prevent it from being installed on a Chrome OS device are reviewed and marked as not required in the manifest.

More info: https://developer.android.com/topic/arc/manifest.html#incompat-entries

Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "UnsupportedChromeOsHardware" as explained in the Suppressing Warnings and Errors section.

UnusedIds

Disabled By: Default

This resource id definition appears not to be needed since it is not referenced from anywhere. Having id definitions, even if unused, is not necessarily a bad idea since they make working on layouts and menus easier, so there is not a strong reason to delete these.

The unused resource check can ignore tests. If you want to include resources that are only referenced from tests, consider packaging them in a test source set instead.

You can include test sources in the unused resource check by setting the system property lint.unused-resources.include-tests=true, and to exclude them (usually for performance reasons), use lint.unused-resources.exclude-tests=true.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "UnusedIds" as explained in the Suppressing Warnings and Errors section.

WrongThreadInterprocedural

Disabled By: Default

Searches for interprocedural call paths that violate thread annotations in the program. Tracks the flow of instantiated types and lambda expressions to increase accuracy across method boundaries.

More info: https://developer.android.com/guide/components/processes-and-threads.html#Threads

To suppress this error, use the issue id "WrongThreadInterprocedural" as explained in the Suppressing Warnings and Errors section.

Suppressing Warnings and Errors

Lint errors can be suppressed in a variety of ways:

1. With a @SuppressLint annotation in the Java code
2. With a tools:ignore attribute in the XML file
3. With a //noinspection comment in the source code
4. With ignore flags specified in the build.gradle file, as explained below
5. With a lint.xml configuration file in the project
6. With a lint.xml configuration file passed to lint via the --config flag
7. With the --ignore flag passed to lint.

To suppress a lint warning with an annotation, add a @SuppressLint("id") annotation on the class, method or variable declaration closest to the warning instance you want to disable. The id can be one or more issue id's, such as "UnusedResources" or {"UnusedResources","UnusedIds"}, or it can be "all" to suppress all lint warnings in the given scope.

To suppress a lint warning with a comment, add a //noinspection id comment on the line before the statement with the error.

To suppress a lint warning in an XML file, add a tools:ignore="id" attribute on the element containing the error, or one of its surrounding elements. You also need to define the namespace for the tools prefix on the root element in your document, next to the xmlns:android declaration:
xmlns:tools="http://schemas.android.com/tools"

To suppress a lint warning in a build.gradle file, add a section like this:

android {
    lintOptions {
        disable 'TypographyFractions','TypographyQuotes'
    }
}

Here we specify a comma separated list of issue id's after the disable command. You can also use warning or error instead of disable to change the severity of issues.

To suppress lint warnings with a configuration XML file, create a file named lint.xml and place it at the root directory of the module in which it applies.

The format of the lint.xml file is something like the following:

<?xml version="1.0" encoding="UTF-8"?>
<lint>
    
    <issue id="all">
        <ignore path="*/test/*" />
    </issue>

    
    <issue id="IconMissingDensityFolder" severity="ignore" />

    
    <issue id="ObsoleteLayoutParam">
        <ignore path="res/layout/activation.xml" />
        <ignore path="res/layout-xlarge/activation.xml" />
        <ignore regexp="(foo|bar).java" />
    </issue>

    
    <issue id="UselessLeaf">
        <ignore path="res/layout/main.xml" />
    </issue>

    
    <issue id="HardcodedText" severity="error" />
</lint>

To suppress lint checks from the command line, pass the --ignore flag with a comma separated list of ids to be suppressed, such as:
$ lint --ignore UnusedResources,UselessLeaf /my/project/path

For more information, see http://g.co/androidstudio/suppressing-lint-warnings