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使用Rhino让java执行javascript的方法实例

2018-10-12 13:59 1431 查看

下载Rhino https://developer.mozilla.org/en-US/docs/Rhino

把js.jar拷贝到项目工程

实现从Java中执行js中的函数、从js中调用Java中的方法,代码:


public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        TextView text1 = (TextView) findViewById(android.R.id.text1);
        TextView text2 = (TextView) findViewById(android.R.id.text2);

        text1.setText(runScript(JAVA_CALL_JS_FUNCTION, "Test", new String[] {}));

        text2.setText(runScript(JS_CALL_JAVA_FUNCTION, "Test", new String[] {}));
    }

    /** Java执行js的方法 */
    private static final String JAVA_CALL_JS_FUNCTION = "function Test(){ return '农民伯伯 java call js Rhino'; }";

    /** js调用Java中的方法 */
    private static final String JS_CALL_JAVA_FUNCTION = //
    "var ScriptAPI = java.lang.Class.forName(\"" + MainActivity.class.getName() + "\", true, javaLoader);" + //
        "var methodRead = ScriptAPI.getMethod(\"jsCallJava\", [java.lang.String]);" + //
        "function jsCallJava(url) {return methodRead.invoke(null, url);}" + //
        "function Test(){ return jsCallJava(); }";

    /**
     * 执行JS
     *
     * @param js js代码
     * @param functionName js方法名称
     * @param functionParams js方法参数
     * @return
     */
    public String runScript(String js, String functionName, Object[] functionParams) {
        Context rhino = Context.enter();
        rhino.setOptimizationLevel(-1);
        try {
            Scriptable scope = rhino.initStandardObjects();

            ScriptableObject.putProperty(scope, "javaContext", Context.javaToJS(MainActivity.this, scope));
            ScriptableObject.putProperty(scope, "javaLoader", Context.javaToJS(MainActivity.class.getClassLoader(), scope));

            rhino.evaluateString(scope, js, "MainActivity", 1, null);

            Function function = (Function) scope.get(functionName, scope);

            Object result = function.call(rhino, scope, scope, functionParams);
            if (result instanceof String) {
                return (String) result;
            } else if (result instanceof NativeJavaObject) {
                return (String) ((NativeJavaObject) result).getDefaultValue(String.class);
            } else if (result instanceof NativeObject) {
                return (String) ((NativeObject) result).getDefaultValue(String.class);
            }
            return result.toString();//(String) function.call(rhino, scope, scope, functionParams);
        } finally {
            Context.exit();
        }
    }

    public static String jsCallJava(String url) {
        return "农民伯伯 js call Java Rhino";
    }
}

注意,混淆的时候js.jar可能混淆不过去,请参照文章4.1的方法。

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