使用Java替换字符串占位符的几种方法_java占位符字符串 替换

一、替换占位符

开发中我们常常要使用变量，这些变量需要根据不同的需求进行一些处理。我们今天来介绍几个使用Java替换字符串占位符的方法。

代码示例如下：

import org.apache.commons.lang.text.StrSubstitutor;

import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Map;

public class Test {
    public static void main(String[] args) {
   		//方法一
		String url = "jdbc:mysql://{ip}:{port}/{tenantCode}?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai";
       String context = url.replace("{ip}", "127.0.0.1").replace("{port}", "3306").replace("{tenantCode}", "test001");

        System.out.println(context);

		//方法二
        String url1 = "jdbc:mysql://%s:%s/%s?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai";
        String context1 = String.format(url1, "127.0.0.1", "3306", "test001");

        System.out.println(context1);

		//方法三
        String url2 = "jdbc:mysql://{0}:{1}/{2}?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai";
        String context2 = MessageFormat.format(url2, "127.0.0.1", "3306", "test001");

        System.out.println(context2);

		//方法四-需要引用commons-lang3或commons-text包
        Map map = new HashMap<>();
        map.put("ip", "127.0.0.1");
        map.put("port", "3306");
        map.put("tenantCode", "test001");
		
        StrSubstitutor strSubstitutor = new StrSubstitutor(map);
        String url3 = "jdbc:mysql://${ip}:${port}/${tenantCode}?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai";
        String context3 = strSubstitutor.replace(url3);
        System.out.println(context3);
    }
}
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打印结果

jdbc:mysql://127.0.0.1:3306/test001?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai
jdbc:mysql://127.0.0.1:3306/test001?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai
jdbc:mysql://127.0.0.1:3306/test001?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai
jdbc:mysql://127.0.0.1:3306/test001?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=Asia/Shanghai
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二、扩展延伸

使用正则表达式动态替换字符串

import java.util.regex.Pattern;

public class Test {
    public static void main(String[] args) {
		// 正则表达式：\ - 需要转义
		String regex = "[|/\\\\]";
		// 需要替换的字符串，把下面字符串变成 abc,def,ghi,123
		String str = "abc|def/ghi\\123";
		
		// 方法一、使用replaceAll
		String newStr1 = str.replaceAll(regex, ",");
		System.out.println(newStr1);
		
		// 方法二、使用Pattern.split, 再使用String.join
		Pattern p = Pattern.compile(regex);
		String[] arr = p.split(str);
		String newStr2 = String.join(",", arr);
		System.out.println(newStr2);
	}
}
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打印结果

abc,def,ghi,123
abc,def,ghi,123
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