java读写ini文件有多种方法，这里将介绍3种方法。

1. 使用工具类Java INI package

该工具的下载和介绍地址是：http://javaini.sourceforge.net/

2.使用工具类ini4j

ini4j的功能强大，但体积也相当大。下载网站：http://ini4j.sourceforge.net/ 下面的例子用java.utils.map来存取ini。

3. 原始方法。 不需要使用任何外部类。下面代码转自他处。

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* 这是个配置文档操作类，用来读取和配置ini配置文档
 
*/
public final class ConfigurationFile {
 /**
 * 从ini配置文档中读取变量的值
 * @param file 配置文档的路径
 * @param section 要获取的变量所在段名称
 * @param variable 要获取的变量名称
 * @param defaultValue 变量名称不存在时的默认值
 * @return 变量的值
 * @throws IOException 抛出文档操作可能出现的io异常
 */
 public static String getProfileString(
 String file,
 String section,
 String variable,
 String defaultValue)
 throws IOException {
 String strLine, value = "";
 BufferedReader bufferedReader = new BufferedReader(new FileReader(file));
 boolean isInSection = false;
 try {
 while ((strLine = bufferedReader.readLine()) != null) {
 strLine = strLine.trim();
 //strLine = strLine.split("[;]")[0];
 Pattern p;
 Matcher m;
 p = Pattern.compile("]");
 m = p.matcher((strLine));
 if (m.matches()) {
 p = Pattern.compile("]");
 m = p.matcher(strLine);
 if (m.matches()) {
 isInSection = true;
 } else {
 isInSection = false;
 }
 }
 if (isInSection == true) {
 strLine = strLine.trim();
 String[] strArray = strLine.split("=");
 if (strArray.length == 1) {
 value = strArray[0].trim();
 if (value.equalsIgnoreCase(variable)) {
 value = "";
 return value;
 }
 } else if (strArray.length == 2) {
 value = strArray[0].trim();
 if (value.equalsIgnoreCase(variable)) {
 value = strArray[1].trim();
 return value;
 }
 } else if (strArray.length > 2) {
 value = strArray[0].trim();
 if (value.equalsIgnoreCase(variable)) {
 value = strLine.substring(strLine.indexOf("=") + 1).trim();
 return value;
 }
 }
 }
 }
 } finally {
 bufferedReader.close();
 }
 return defaultValue;
 }
 /**
 * 修改ini配置文档中变量的值
 * @param file 配置文档的路径
 * @param section 要修改的变量所在段名称
 * @param variable 要修改的变量名称
 * @param value 变量的新值
 * @throws IOException 抛出文档操作可能出现的io异常
 */
 public static boolean setProfileString(
 String file,
 String section,
 String variable,
 String value)
 throws IOException {
 String fileContent, allLine,strLine, newLine, remarkStr;
 String getValue;
 BufferedReader bufferedReader = new BufferedReader(new FileReader(file));
 boolean isInSection = false;
 fileContent = "";
 try {
 
 while ((allLine = bufferedReader.readLine()) != null) {
 allLine = allLine.trim();
 System.out.println("allLine == "+allLine);
 strLine = allLine;
 Pattern p;
 Matcher m;
 p = Pattern.compile("]");
 m = p.matcher((strLine));
 //System.out.println("+++++++ ");
 if (m.matches()) {
 System.out.println("+++++++ ");
 p = Pattern.compile("]");
 m = p.matcher(strLine);
 if (m.matches()) {
 System.out.println("true ");
 isInSection = true;
 } else {
 isInSection = false;
 System.out.println("+++++++ ");
 }
 }
 
 if (isInSection == true) {
 
 strLine = strLine.trim();
 String[] strArray = strLine.split("=");
 getValue = strArray[0].trim();
 
 if (getValue.equalsIgnoreCase(variable)) {
 // newLine = getValue + " = " + value + " " + remarkStr;
 
 newLine = getValue + " = " + value + " ";
 fileContent += newLine + "\r\n";
 while ((allLine = bufferedReader.readLine()) != null) {
 fileContent += allLine + "\r\n";
 }
 bufferedReader.close();
 BufferedWriter bufferedWriter =
 new BufferedWriter(new FileWriter(file, false));
 bufferedWriter.write(fileContent);
 bufferedWriter.flush();
 bufferedWriter.close();
 
 return true;
 }
 }
 fileContent += allLine + "\r\n";
 }
 }catch(IOException ex){
 throw ex;
 } finally {
 bufferedReader.close();
 }
 return false;
 }
 public static void main(String[] args) {
//String value = Config.getProfileString("sysconfig.ini", "Option", "OracleDB", "default");
//System.out.println(value);
 try {
 
 System.out.println("值已经改变!... "+ConfigurationFile.setProfileString("E:/web5/h2_test/gamewww.ini", "TestSect1", "10012", "111111"));
 
 System.out.println("值读取成功!... "+ConfigurationFile.getProfileString("E:/web5/h2_test/gamewww.ini", "TestSect1", "10012", ""));
 
 } catch (IOException e) {
 System.out.println("错误 ......"+e.toString());
 }
 }
}