Merge "Fix NPE when a test class has uninitialized mock fields"
am: 3b8f899939

Change-Id: I6ade795ad32d7172837332c873207f4ef32c1e19
tree: 1f52b24faac0df61d9246b5c952cffe8374ba07a
  1. dexmaker/
  2. dx/
  3. javadoc/
  4. lib/
  5. mockito/
  6. Android.mk
  7. bug-8108255.patch
  8. build.gradle
  9. build.xml
  10. CleanSpec.mk
  11. COPYING
  12. LICENSE.txt
  13. MODULE_LICENSE_APACHE2
  14. NOTICE
  15. pom.xml
  16. README.android
  17. README.md
README.md

A Java-language API for doing compile time or runtime code generation targeting the Dalvik VM. Unlike cglib or ASM, this library creates Dalvik .dex files instead of Java .class files.

It has a small, close-to-the-metal API. This API mirrors the Dalvik bytecode specification giving you tight control over the bytecode emitted. Code is generated instruction-by-instruction; you bring your own abstract syntax tree if you need one. And since it uses Dalvik's dx tool as a backend, you get efficient register allocation and regular/wide instruction selection for free.

Class Proxies

Dexmaker includes a stock code generator for class proxies. If you just want to do AOP or class mocking, you don't need to mess around with bytecodes.

Mockito Mocks

Dexmaker includes class proxy support for Mockito. Add the mockito and the dexmaker .jar files to your Android test project's libs/ directory and you can use Mockito in your Android unit tests.

This requires Mockito 1.10.5 or newer.

Runtime Code Generation

This example generates a class and a method. It then loads that class into the current process and invokes its method.

public final class HelloWorldMaker {
    public static void main(String[] args) throws Exception {
        DexMaker dexMaker = new DexMaker();

        // Generate a HelloWorld class.
        TypeId<?> helloWorld = TypeId.get("LHelloWorld;");
        dexMaker.declare(helloWorld, "HelloWorld.generated", Modifier.PUBLIC, TypeId.OBJECT);
        generateHelloMethod(dexMaker, helloWorld);

        // Create the dex file and load it.
        File outputDir = new File(".");
        ClassLoader loader = dexMaker.generateAndLoad(HelloWorldMaker.class.getClassLoader(),
                outputDir, outputDir);
        Class<?> helloWorldClass = loader.loadClass("HelloWorld");

        // Execute our newly-generated code in-process.
        helloWorldClass.getMethod("hello").invoke(null);
    }

    /**
     * Generates Dalvik bytecode equivalent to the following method.
     *    public static void hello() {
     *        int a = 0xabcd;
     *        int b = 0xaaaa;
     *        int c = a - b;
     *        String s = Integer.toHexString(c);
     *        System.out.println(s);
     *        return;
     *    }
     */
    private static void generateHelloMethod(DexMaker dexMaker, TypeId<?> declaringType) {
        // Lookup some types we'll need along the way.
        TypeId<System> systemType = TypeId.get(System.class);
        TypeId<PrintStream> printStreamType = TypeId.get(PrintStream.class);

        // Identify the 'hello()' method on declaringType.
        MethodId hello = declaringType.getMethod(TypeId.VOID, "hello");

        // Declare that method on the dexMaker. Use the returned Code instance
        // as a builder that we can append instructions to.
        Code code = dexMaker.declare(hello, Modifier.STATIC | Modifier.PUBLIC);

        // Declare all the locals we'll need up front. The API requires this.
        Local<Integer> a = code.newLocal(TypeId.INT);
        Local<Integer> b = code.newLocal(TypeId.INT);
        Local<Integer> c = code.newLocal(TypeId.INT);
        Local<String> s = code.newLocal(TypeId.STRING);
        Local<PrintStream> localSystemOut = code.newLocal(printStreamType);

        // int a = 0xabcd;
        code.loadConstant(a, 0xabcd);

        // int b = 0xaaaa;
        code.loadConstant(b, 0xaaaa);

        // int c = a - b;
        code.op(BinaryOp.SUBTRACT, c, a, b);

        // String s = Integer.toHexString(c);
        MethodId<Integer, String> toHexString
                = TypeId.get(Integer.class).getMethod(TypeId.STRING, "toHexString", TypeId.INT);
        code.invokeStatic(toHexString, s, c);

        // System.out.println(s);
        FieldId<System, PrintStream> systemOutField = systemType.getField(printStreamType, "out");
        code.sget(systemOutField, localSystemOut);
        MethodId<PrintStream, Void> printlnMethod = printStreamType.getMethod(
                TypeId.VOID, "println", TypeId.STRING);
        code.invokeVirtual(printlnMethod, null, localSystemOut, s);

        // return;
        code.returnVoid();
    }
}

Use it in your app

Maven users can get dexmaker from Sonatype's central repository. The Mockito dependency is optional.

  <dependency>
    <groupId>com.google.dexmaker</groupId>
    <artifactId>dexmaker</artifactId>
    <version>1.2</version>
  </dependency>
  <dependency>
    <groupId>com.google.dexmaker</groupId>
    <artifactId>dexmaker-mockito</artifactId>
    <version>1.2</version>
  </dependency>

Download dexmaker-1.2.jar and dexmaker-mockito-1.2.jar.

Run the Unit Tests

The unit tests for dexmaker must be run on a dalvikvm. In order to do this, you can use Vogar in the following fashion:

$ java -jar vogar.jar --mode device --sourcepath /path/to/dexmaker/dexmaker/src/test/java --sourcepath /path/to/dexmaker/dexmaker/src/main/java --sourcepath /path/to/dexmaker/dx/src/main/java --device-dir /data/dexmaker /path/to/dexmaker/dexmaker/src/test/

Download vogar.jar.