Pre-General Availability: 2017-05-24

jdeprscan

You use the jdeprscan tool as a static analysis tool that scans a jar file (or some other aggregation of class files) for uses of deprecated API elements.

Synopsis

jdeprscan [ options ]{dir|jar|class}
options

See Options for the jdeprscan Command

dir|jar|class

jdeprscan command scans each argument for usages of deprecated APIs. The arguments can be a:

  • dir: Directory

  • jar: JAR file

  • class: Class name or class file

The class name should use dot (.) as a separator. For example:

java.lang.Thread

For nested classes, the $ separator character should be used. For example:

java.lang.Thread$State

A class file can also be named. For example:

build/classes/java/lang/Thread$State.class

Description

The jdeprscan tool is a static analysis tool provided by the JDK that scans a JAR file or some other aggregation of class files for uses of deprecated API elements. The deprecated APIs identified by the jdeprscan tool are only those that are defined by Java SE. Deprecated APIs defined by third party libraries aren’t reported.

To scan a JAR file or a set of class files, you must first ensure that all of the classes that the scanned classes depend upon are present in the class path. Set the class path using the --class-path option described in Options for the jdeprscan Command). Typically, you would use the same class path as the one you use when invoking your application.

If jdeprscan can’t find all the dependent classes, it will issue an error message for each class that's missing. These error messages are typically of the form:

error: cannot find class ...  

If these errors occur, you must adjust the class path so that it includes all dependent classes.

Options for the jdeprscan Command

The following options are available:

--class-path PATH

Provides a search path for resolution of dependent classes

--for-removal

Limits scanning or listing to APIs that are deprecated for removal. Can’t be used with a release value of 6, 7, or 8.

--full-version

Prints out the full version string of the tool.

--help or —h

Prints out a full help message.

--list or —l

Prints out the set of deprecated APIs. No scanning is done, so no directory, jar, or class arguments should be provided.

--release 6|7|8|9

Specifies the Java SE release that provides the set of deprecated APIs for scanning.

--verbose or —v

Enables additional message output during processing.

--version

Prints out the abbreviated version string of the tool.

Example of jdeprscan Output

The JAR file for this library will be named something similar to commons-math3-3.6.1.jar. To scan this JAR file for the use of deprecated APIs, run the following command:

jdeprscan commons-math3-3.6.1.jar 

This command produces several lines of output. For example, one line of output might be:

class org/apache/commons/math3/util/MathUtils uses deprecated method java/lang/Double::<init>(D)V

Note:

The class name is specified using the slash-separated binary name as described in JVMS 4.2.1. This is the form used internally in class files.

The deprecated API it uses is a method on the java.lang.Double class. Notice the slash-separated name in the output.

The name of the deprecated method is <init>, which is a special name that means that the method is actually a constructor. Another special name is <clinit>, which indicates a class static initializer.

Other methods are just listed by their method name. Following the method name is the argument list and return type:

(D)V

This indicates that it takes a single double value (a primitive) and returns void. The argument and return types can become cryptic. For example, another line of output might be:

class org/apache/commons/math3/util/Precision uses deprecated method java/math/BigDecimal::setScale(II)Ljava/math/BigDecimal;   

In this line of output, the deprecated method is on class java.math.BigDecimal, and the method is setScale(). In this case, the (II) means that it takes two int arguments . The Ljava/math/BigDecimal; after the parentheses means that it returns a reference to java.math.BigDecimal.