java - JDB 整数映射查找

Question

我正在调试一些使用 Map<Integer,...> 的代码，但我很难找到与各种 Integer 相关的值!这是一个最小的工作示例:

java代码(保存到.\src):

import java.util.Map;
import java.util.HashMap;

public class Hello {

    public static void main(String[] args) throws java.io.IOException {
        Map<Integer,String> mymap = new HashMap<Integer,String>(2);
        mymap.put(new Integer(5), "five");
        mymap.put(6, "six");
    }
}

终端 1(powershell):

javac -g $(ls . *.java -r -name)
java -cp src -Xdebug '-Xrunjdwp:transport=dt_shmem,server=y,suspend=y,address=hey' Hello

终端 2(powershell):

jdb -attach hey

...

VM Started: No frames on the current call stack

main[1] stop at Hello:10
Deferring breakpoint Hello:10.
It will be set after the class is loaded.
main[1] cont
> Set deferred breakpoint Hello:10

Breakpoint hit: "thread=main", Hello.main(), line=10 bci=40

main[1] dump mymap.get(5)
com.sun.jdi.InvalidTypeException: Can't assign primitive value to object
 mymap.get(5) = null
main[1] dump mymap.get(new Integer(5))
com.sun.tools.example.debug.expr.ParseException: No class named: Integer
 mymap.get(new Integer(5)) = null
main[1]

我应该如何从 Map<Integer,?> 中查找值？

Answer 1

使用完全限定的类名:

dump mymap.get(new java.lang.Integer(5))