Question

我是java的新手。我正在尝试创建一个项目，使用JavaParser从所需的.java文件获取类名，字段名。但我得到一个错误，我对此错误一无所知。如何修复该错误？

1-）首先，我在NetBeans IDE上创建一个新项目

2-）在项目文件夹中添加JavaParser依赖项pom.xml文件和“mvn clean install”。（可能我做错了）

3-）创建文件并输入以下代码

4-）编译，我得到以下错误：

Exception in thread "main" java.lang.ClassFormatError: Invalid superclass index 0 in class file com/github/javaparser/JavaParser
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at parser.GetTypes.parseClassname(GetTypes.java:28)
    at parser.Parser.main(Parser.java:28)
C:\Users\q\AppData\Local\NetBeans\Cache\8.2\executor-snippets\run.xml:53: Java returned: 1
BUILD FAILED (total time: 0 seconds)

Parser.java文件（src / parser / Parser.java）：

package parser;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class Parser {

  public static void main(String[] args) throws FileNotFoundException  { 
   System.out.println(GetTypes.parseClassname(new File("C:\\HelloOOPP.java")));
    }
  }

GetTypes.java文件（src / parser / GetTypes.java）：

package parser;
import com.github.javaparser.*;
import com.github.javaparser.ast.*;
import com.github.javaparser.ast.body.*;
import com.github.javaparser.symbolsolver.model.declarations.TypeDeclaration;
import java.io.*;
import java.util.*;
import java.lang.*;
import java.lang.reflect.Field;
public class GetTypes {
    public static String parseClassname(File filename) throws FileNotFoundException   {

            FileInputStream fin = new FileInputStream(filename);
            CompilationUnit cu = JavaParser.parse(fin);
           // String packagePrefix = cu.getPackage().getName().toString();
            //if (!packagePrefix.isEmpty()) packagePrefix += ".";
            StringBuilder build=new  StringBuilder();
            for (TypeDeclaration type : cu.getTypes())
            {
                if (type.isClass())
                { 
                    build.append("Class Name:");
                    build.append(type.getName());
                    build.append("\n");
                    build.append("Fields");
                    //build.append(Get_Fields(type));
                }                   
            }
            return build.toString();      
    }   
     private String Get_Fields(TypeDeclaration c) //
     {
         Field[] fields = c.getClass().getFields();
         StringBuilder str=new StringBuilder();
         for(int i=0;i<fields.length;i++)
         {
             str.append(fields[i].getName());
             str.append("\n");
         }
         return str.toString();
     }
     /*
     private int Count_Fields(TypeDeclaration c)
     {   
     }*/

}

pom.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <!-- This is often your domain name (reversed.)  -->
    <groupId>com.parser</groupId>
    <!-- The name of this project (actually, the name of the artifact, which is the thing that this project produces. A jar in this case.) -->
    <artifactId>parser</artifactId>
    <!-- The version of this project. SNAPSHOT means "we're still working on it" -->
    <version>1.0-SNAPSHOT</version>

    <properties>
        <!-- Tell Maven we want to use Java 8 -->
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <!-- Tell Maven to treat all source files as UTF-8 -->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <!-- Here are all your dependencies. Currently only one. These are automatically downloaded from https://mvnrepository.com/ -->
        <dependency>
            <groupId>com.github.javaparser</groupId>
            <artifactId>javaparser-symbol-solver-core</artifactId>
            <version>3.5.16</version>
        </dependency>
    </dependencies>
</project>

cmd上的mvn clean install：

C:\parser>mvn clean install
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building parser 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ parser ---
[INFO] Deleting C:\parser\target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ parser ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\parser\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ parser ---
[INFO] No sources to compile
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ parser ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\parser\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ parser ---
[INFO] No sources to compile
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ parser ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ parser ---
[WARNING] JAR will be empty - no content was marked for inclusion!
[INFO] Building jar: C:\parser\target\parser-1.0-SNAPSHOT.jar
[INFO]
[INFO] --- maven-install-plugin:2.4:install (default-install) @ parser ---
[INFO] Installing C:\parser\target\parser-1.0-SNAPSHOT.jar to C:\Users\q\.m2\repository\com\parser\parser\1.0-SNAPSHOT\parser-1.0-SNAPSHOT.jar
[INFO] Installing C:\parser\pom.xml to C:\Users\q\.m2\repository\com\parser\parser\1.0-SNAPSHOT\parser-1.0-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.193 s
[INFO] Finished at: 2018-03-08T16:41:28+03:00
[INFO] Final Memory: 12M/155M
[INFO] ------------------------------------------------------------------------

Answer 1

我的错。问题是“在我的项目中使用netbeans结构并尝试使用maven添加包”。我创建一个新文件并按照本教程创建文件结构：maven file structure 为这个结构实现我的代码，并且每个人都可以正常工作

java.lang.ClassFormatError：类文件com / github / javaparser / JavaParser

1 个答案: