java 获取本地ip，更改ip。并附上java程序打jar包，做exe文件的全过程

获取本地IP的Java代码：

import java.net.InetAddress;
import java.net.UnknownHostException;
    
public class GetLocalIP {
    public static void main(String[] args) throws UnknownHostException {
        InetAddress addr = InetAddress.getLocalHost();
        System.out.println("Local HostAddress: "+addr.getHostAddress());
    }
}

更改本地IP的Java代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class ChangeLocalIP {
    public static void main(String[] args) {
        List<String> commandList = new ArrayList<String>();
        commandList.add("netsh");
        commandList.add("interface");
        commandList.add("ipv4");
        commandList.add("set");
        commandList.add("address");
        commandList.add("name=\"以太网\"", "static", "192.168.1.100", "255.255.255.0", "192.168.1.1");
        try {
            ProcessBuilder builder = new ProcessBuilder(commandList);
            Process process = builder.start();
            BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
            int exitCode = process.waitFor();
            System.out.println("\nExited with error code: " + exitCode);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

打包jar文件：

javac GetLocalIP.java
jar cvfm GetLocalIP.jar manifest.txt GetLocalIP.class

其中，`manifest.txt` 的内容如下：

Main-Class: GetLocalIP

打包exe文件：

1. 在 Windows 系统上安装 Launch4j（http://launch4j.sourceforge.net/）。
2. 使用 Launch4j 创建一个 XML 配置文件，如下：

<launch4jConfig>
  <headerType>gui</headerType>
  <jar>D:\workspace\GetLocalIP.jar</jar>
  <outfile>D:\workspace\GetLocalIP.exe</outfile>
  <errTitle></errTitle>
  <classPath>
    <mainClass>GetLocalIP</mainClass>
    <preCp>anything</preCp>
  </classPath>
  <jre>
    <minVersion>1.6.0</minVersion>
    <jdkPreference>preferJre</jdkPreference>
  </jre>
  <versionInfo>
    <fileVersion>1.0.0.0</fileVersion>
    <txtFileVersion>1.0.0</txtFileVersion>
    <fileDescription>GetLocalIP</fileDescription>
    <productVersion>1.0.0.0</productVersion>
    <txtProductVersion>1.0.0</txtProductVersion>
    <productName>GetLocalIP</productName>
    <companyName>My Company Name</companyName>
    <internalName>GetLocalIP</internalName>
    <originalFilename>GetLocalIP.exe</originalFilename>
  </versionInfo>
</launch4jConfig>

3. 在 Launch4j 窗口中加载这个 XML 配置文件并生成 exe 文件。