尝试添加一行来创建 Map 时出现 Javassist CannotCompileException

Question

嗯尝试检测一种方法来完成以下任务。 任务 - 创建映射并将值插入到映射中添加 System.out.println 行不会导致任何异常。但是，当我添加行来创建 map 时，由于缺少;，它会抛出cannotCompileException。当我打印最后的字符串时，它似乎没有遗漏任何字符串。我在这里做错了什么。

public void createInsertAt(CtMethod method, int lineNo, Map<String,String> parameterMap)
            throws CannotCompileException {
        StringBuilder atBuilder = new StringBuilder();
        atBuilder.append("System.out.println(\"" + method.getName() + " is running\");");
        atBuilder.append("java.util.Map<String,String> arbitraryMap = new java.util.HashMap<String,String>();");

        for (Map.Entry<String,String> entry : parameterMap.entrySet()) {
        }
        System.out.println(atBuilder.toString());
        method.insertAt(1, atBuilder.toString());
    }

打印字符串生成器的输出得到的字符串是，

System.out.println("prepareStatement is running");java.util.Map arbitraryMap = new java.util.HashMap();

收到的异常是，

javassist.CannotCompileException: [source error] ; is missing
    at javassist.CtBehavior.insertAt(CtBehavior.java:1207)
    at javassist.CtBehavior.insertAt(CtBehavior.java:1134)
    at org.wso2.das.javaagent.instrumentation.InstrumentationClassTransformer.createInsertAt(InstrumentationClassTransformer.java:126)
    at org.wso2.das.javaagent.instrumentation.InstrumentationClassTransformer.instrumentMethod(InstrumentationClassTransformer.java:100)
    at org.wso2.das.javaagent.instrumentation.InstrumentationClassTransformer.transform(InstrumentationClassTransformer.java:37)
    at sun.instrument.TransformerManager.transform(TransformerManager.java:188)
    at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:424)
    at sun.instrument.InstrumentationImpl.retransformClasses0(Native Method)
    at sun.instrument.InstrumentationImpl.retransformClasses(InstrumentationImpl.java:144)
    at org.wso2.das.javaagent.instrumentation.Agent.premain(Agent.java:39)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:382)
    at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:397)
Caused by: compile error: ; is missing
    at javassist.compiler.Parser.parseDeclarationOrExpression(Parser.java:594)
    at javassist.compiler.Parser.parseStatement(Parser.java:277)
    at javassist.compiler.Javac.compileStmnt(Javac.java:567)
    at javassist.CtBehavior.insertAt(CtBehavior.java:1186)
    ... 15 more

(有什么方法可以调试此类问题。)请提供一些帮助......

Answer 1

Javassist 的编译器不支持泛型。删除或注释掉它们:

.append("java.util.Map arbitraryMap = new java.util.HashMap();")

或

.append("java.util.Map/*<String,String>*/ arbitraryMap = new java.util.HashMap/*<String,String>*/();")

后者仅作为您自己的注释有用，当然，它对 Javassist 没有特殊意义。