Java CodeAttribute.getAttribute方法代码示例

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * 获取方法的参数名
 * @param clazz  类
 * @param method 方法
 * @return 方法名称数组
 * @throws NotFoundException .{@link NotFoundException}
 */
public static String[] getParamNames(Class clazz, String method) throws NotFoundException {
    ClassPool pool = ClassPool.getDefault();
    CtClass cc = pool.get(clazz.getName());
    CtMethod cm = cc.getDeclaredMethod(method);
    // 使用javaassist的反射方法获取方法的参数名
    MethodInfo methodInfo = cm.getMethodInfo();
    CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
    LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
    if (attr == null) {
        throw new NotFoundException("cannot get LocalVariableAttribute");
    }
    String[] paramNames = new String[cm.getParameterTypes().length];
    int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;
    for (int i = 0; i < paramNames.length; i++) {
        paramNames[i] = attr.variableName(i + pos);
    }
    return paramNames;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * get method parameter names
 * @param cls
 * @param method
 * @return
 * @throws Exception
 */
public static String[] getParamNames(Class<?> cls, Method method) throws Exception {
    ClassPool pool = ClassPool.getDefault();
    CtClass cc = pool.get(cls.getName());

    Class<?>[] paramAry = method.getParameterTypes();
    String[] paramTypeNames = new String[paramAry.length];
    for (int i = 0; i < paramAry.length; i++) {
        paramTypeNames[i] = paramAry[i].getName();
    }

    CtMethod cm = cc.getDeclaredMethod(method.getName(), pool.get(paramTypeNames));

    MethodInfo methodInfo = cm.getMethodInfo();
    CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
    LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
    if (attr == null) {
        throw new Exception("class:" + cls.getName() + ", have no LocalVariableTable, please use javac -g:{vars} to compile the source file");
    }
    String[] paramNames = new String[cm.getParameterTypes().length];
    int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;
    for (int i = 0; i < paramNames.length; i++) {
        paramNames[i] = attr.variableName(i + pos);
    }
    return paramNames;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * 获取方法参数名
 * @param method
 * @return 
 */
public static String[] getParamName(Method method) throws Exception {
	ClassPool pool = ClassPool.getDefault();
	CtClass ctClass = pool.get(method.getDeclaringClass().getName());
	CtMethod ctMethod = ctClass.getDeclaredMethod(method.getName());
	// 使用javassist的反射方法的参数名
	MethodInfo methodInfo = ctMethod.getMethodInfo();
	CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
	LocalVariableAttribute attr = (LocalVariableAttribute) 
		codeAttribute.getAttribute(LocalVariableAttribute.tag);

	int length = ctMethod.getParameterTypes().length;
	String[] array = new String[length];
	for (int i = 0; i < length; i++) {
		array[i] = attr.variableName(i + 1);
	}
	return array;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
public void rename(CtClass c) {
	for (CtBehavior behavior : c.getDeclaredBehaviors()) {
		
		// if there's a local variable table, just rename everything to v1, v2, v3, ... for now
		CodeAttribute codeAttribute = behavior.getMethodInfo().getCodeAttribute();
		if (codeAttribute == null) {
			continue;
		}
		
		BehaviorEntry behaviorEntry = EntryFactory.getBehaviorEntry(behavior);
		ConstPool constants = c.getClassFile().getConstPool();
		
		LocalVariableAttribute table = (LocalVariableAttribute)codeAttribute.getAttribute(LocalVariableAttribute.tag);
		if (table != null) {
			renameLVT(behaviorEntry, constants, table);
		}
		
		LocalVariableTypeAttribute typeTable = (LocalVariableTypeAttribute)codeAttribute.getAttribute(LocalVariableAttribute.typeTag);
		if (typeTable != null) {
			renameLVTT(typeTable, table);
		}
	}
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
private void initMethodParamInfo(Object controller, String methodName) {
	methodParamInfo = new LinkedHashMap<Class<?>, String>();
	Class<?> clazz = controller.getClass();
	try {
		ClassPool classPool = ClassPool.getDefault();
		classPool.insertClassPath(new ClassClassPath(clazz));
		CtClass ctClass = classPool.get(clazz.getName());
		CtMethod ctMethod = ctClass.getDeclaredMethod(methodName);

		MethodInfo methodInfo = ctMethod.getMethodInfo();
		CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
		LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute
				.getAttribute("LocalVariableTable");

		CtClass[] parameterTypes = ctMethod.getParameterTypes();
		int pos = Modifier.isStatic(ctMethod.getModifiers()) ? 0 : 1;
		for (int i = 0; i < parameterTypes.length; i++)
			methodParamInfo.put(Class.forName(parameterTypes[i].getName()),
					attr.variableName(i + pos));
	} catch (Exception e) {
		throw new RuntimeException(e.getMessage());
	}
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * Get method arg names.
 *
 * @param clazz
 * @param methodName
 * @return
 */
public static <T> String[] getMethodArgNames(Class<T> clazz, String methodName) {
    try {
        ClassPool pool = ClassPool.getDefault();
        CtClass cc = pool.get(clazz.getName());

        CtMethod cm = cc.getDeclaredMethod(methodName);

        // 使用javaassist的反射方法获取方法的参数名
        MethodInfo methodInfo = cm.getMethodInfo();
        CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
        LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
        if (attr == null) {
            throw new RuntimeException("LocalVariableAttribute of method is null! Class " + clazz.getName() + ",method name is " + methodName);
        }
        String[] paramNames = new String[cm.getParameterTypes().length];
        int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;
        for (int i = 0; i < paramNames.length; i++)
            paramNames[i] = attr.variableName(i + pos);

        return paramNames;
    } catch (NotFoundException e) {
        throw new RuntimeException(e.getMessage(), e);
    }
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * Get method variable names for the provided method.
 * 
 * @param classname String
 * @param methodname String
 * @return the String[] of method variable name.
 */
public static String[] getMethodVariableName(String classname, String methodname) {
  try {
    ClassPool pool = ClassPool.getDefault();
    CtClass cc = pool.get(classname);
    CtMethod cm = cc.getDeclaredMethod(methodname);
    MethodInfo methodInfo = cm.getMethodInfo();
    CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
    String[] paramNames = new String[cm.getParameterTypes().length];
    LocalVariableAttribute attr =
        (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
    if (attr != null) {
      int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;
      for (int i = 0; i < paramNames.length; i++) {
        paramNames[i] = attr.variableName(i + pos);
      }
      return paramNames;
    }
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
  return null;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * Records local variables available at the specified program counter.
 * If the LocalVariableAttribute is not available, this method does not
 * record any local variable.  It only returns false.
 *
 * @param pc    program counter (>= 0)
 * @return false if the CodeAttribute does not include a
 *              LocalVariableAttribute.
 */
public boolean recordLocalVariables(CodeAttribute ca, int pc)
    throws CompileError
{
    LocalVariableAttribute va
        = (LocalVariableAttribute)
          ca.getAttribute(LocalVariableAttribute.tag);
    if (va == null)
        return false;

    int n = va.tableLength();
    for (int i = 0; i < n; ++i) {
        int start = va.startPc(i);
        int len = va.codeLength(i);
        if (start <= pc && pc < start + len)
            gen.recordVariable(va.descriptor(i), va.variableName(i),
                               va.index(i), stable);
    }

    return true;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * Records parameter names if the LocalVariableAttribute is available.
 * It returns false unless the LocalVariableAttribute is available.
 *
 * @param numOfLocalVars    the number of local variables used
 *                          for storing the parameters.
 * @return false if the CodeAttribute does not include a
 *              LocalVariableAttribute.
 */
public boolean recordParamNames(CodeAttribute ca, int numOfLocalVars)
    throws CompileError
{
    LocalVariableAttribute va
        = (LocalVariableAttribute)
          ca.getAttribute(LocalVariableAttribute.tag);
    if (va == null)
        return false;

    int n = va.tableLength();
    for (int i = 0; i < n; ++i) {
        int index = va.index(i);
        if (index < numOfLocalVars)
            gen.recordVariable(va.descriptor(i), va.variableName(i),
                               index, stable);
    }

    return true;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
public static String[] getReflectParamName(Class<?> clazz, String methodName) {
	String[] paramNames = null;
	try {
		ClassPool pool = ClassPool.getDefault();
		CtClass cc = pool.get(clazz.getName());
		CtMethod cm = cc.getDeclaredMethod(methodName);
		// 使用javaassist的反射方法获取方法的参数名
		MethodInfo methodInfo = cm.getMethodInfo();
		CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
		LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
		if (attr == null) {
			// exception
		}
		paramNames = new String[cm.getParameterTypes().length];
		int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;
		for (int i = 0; i < paramNames.length; i++)
			paramNames[i] = attr.variableName(i + pos);
	} catch (NotFoundException e) {
		e.printStackTrace();
	}
	return paramNames;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * 通过Javaassist获取方法的参数名
 */
public static String[] getMethodArgNames(String className, String methodName){
    List<String> names = new ArrayList<String>();
    try {
        ClassPool classPool = ClassPool.getDefault();
        classPool.insertClassPath(new ClassClassPath(ReflectUtil.class));
        CtClass ctClass = classPool.getCtClass(className);
        CtMethod method = ctClass.getDeclaredMethod(methodName);
        MethodInfo methodInfo = method.getMethodInfo();
        CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
        LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
        if (attr == null)  {
            return (String[])names.toArray();
        }
        int argNum = method.getParameterTypes().length;
        int pos = javassist.Modifier.isStatic(method.getModifiers()) ? 0 : 1;
        for (int i=0; i<argNum; i++) {
            names.add(attr.variableName(i + pos));
        }
    } catch (NotFoundException e) {
        log.error(e);
    }
    return names.toArray(new String[0]);
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
static void tes() throws NotFoundException {
    ClassPool classPool = ClassPool.getDefault();
    CtClass ctClass = classPool.get("org.rural.test.Test");
    CtMethod[] methods = ctClass.getDeclaredMethods();
    for(CtMethod method : methods){
        MethodInfo methodInfo = method.getMethodInfo();
        CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
        LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
        if (attr == null)  {
            return;
        }
        String[] paramNames = new String[method.getParameterTypes().length];
        int pos = Modifier.isStatic(method.getModifiers()) ? 0 : 1;
        for (int i = 0; i < paramNames.length; i++)
            paramNames[i] = attr.variableName(i + pos);
    }
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
public static LocalVariableAttribute getLocalVariableAttribute(String className, String methodName) throws NotFoundException {
	ClassPool clsPool = ClassPool.getDefault();
	
	CtClass ctCls = clsPool.get(className);
	CtMethod[] ctMethods = ctCls.getMethods();
	CtMethod ctMethod = null;
	
	for(CtMethod methodTmp : ctMethods) {
		if(methodTmp.getName().equals(methodName)
				&& (methodTmp.getModifiers() & Modifier.PUBLIC) != 0
				) {
			ctMethod = methodTmp;
			break;
		}
	}

	MethodInfo methodInfo = ctMethod.getMethodInfo();
	CodeAttribute codeAttr = methodInfo.getCodeAttribute();
	LocalVariableAttribute localVarAttr = (LocalVariableAttribute) codeAttr.getAttribute(LocalVariableAttribute.tag);

	return localVarAttr;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
private Map<Integer, String> extractNameParameter(CtMethod m) throws NotFoundException {
    Map<Integer, String> hashNameParam = new HashMap<Integer, String>();
    CodeAttribute codeAttribute = (CodeAttribute) m.getMethodInfo().getAttribute("Code");
    if (codeAttribute != null) {
        LocalVariableAttribute localVariableAttribute = (LocalVariableAttribute) codeAttribute.getAttribute("LocalVariableTable");
        if (localVariableAttribute != null && localVariableAttribute.tableLength() >= m.getParameterTypes().length) {
            for (int i = 0; i < m.getParameterTypes().length + 2; i++) {
                String name = localVariableAttribute.getConstPool().getUtf8Info(localVariableAttribute.nameIndex(i));
                if (!name.equals("this")) {
                    hashNameParam.put(i, name);
                }
            }
        }
    }
    return hashNameParam;
}
 

import javassist.bytecode.CodeAttribute; //导入方法依赖的package包/类
/**
 * get LocalVariableAttribute
 *
 * @param method
 * @return null if the class is not compiled with debug option
 */
public static LocalVariableAttribute lookupLocalVariableAttribute(CtBehavior method) {
    if (method == null) {
        throw new NullPointerException("method must not be null");
    }
    MethodInfo methodInfo = method.getMethodInfo2();
    CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
    
    if (codeAttribute == null) {
        return null;
    }
    
    AttributeInfo localVariableTable = codeAttribute.getAttribute(LocalVariableAttribute.tag);
    LocalVariableAttribute local = (LocalVariableAttribute) localVariableTable;
    return local;
}