Question

我在下面的路径中有一个TEST123.class。

d：/用户/ XXX /桌面/ SEM-材料在职/ SEM-材料在职/ SEM-材料freemarkerjob /目标/类/ COM /携程/市场/ SEM / freemarkerjob / dynamicjava /

然后我运行下面的try子句通过URLClassLoader加载类，但它给我异常ava.lang.NoClassDefFoundError：TEST123（错误的名称：，如何解决异常？

ava.lang.NoClassDefFoundError: TEST123 (wrong name: com/ctrip/market/sem/freemarkerjob/dynamicjava/TEST123)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)

   try {
                URLClassLoader mycl = new URLClassLoader(new URL[] { new URL(
                        "file:///D:/Users/XXX/Desktop/sem-material-job/sem-material-job/sem-material-freemarkerjob/target/classes/com/ctrip/market/sem/freemarkerjob/dynamicjava/") });
                Class c2 = mycl.loadClass("TEST123");
            } catch (Exception e) {
                e.printStackTrace();
            }

Answer 1

您正在尝试加载课程TEST123，但您的TEST123.class文件包含课程com.ctrip.market.sem.freemarkerjob.dynamicjava.TEST123。 TEST123.java第一行的包裹是什么？将代码更改为

URLClassLoader mycl = new URLClassLoader(new URL[] { 
        new URL("file:///D:/Users/XXX/Desktop/sem-material-job/sem-material-job/sem-material-freemarkerjob/target/classes/") });
Class c2 = mycl.loadClass("com.ctrip.market.sem.freemarkerjob.dynamicjava.TEST123");

应该工作。

Answer 2

我认为您必须将URL更改为指向类路径并按包名加载类，如此

URLClassLoader mycl = new URLClassLoader(new URL[] { 
new URL("file:///D:/Users/XXX/Desktop/sem-material-job/sem-material-‌job/sem-material-fre‌emarkerjob/target/cl‌asses/") }); 

Class c2 = mycl.loadClass("com.ctrip.market.sem.freemarkerjob.dynamicja‌va.TEST123");

得到NoClassDefFoundError：Windows路径

2 个答案: