Java如何使用正则表达式从字符串中提取字符串或数字呢?

从字符串中提取字符串和数字的实现思路:
       定义合适的正则表达式,然后提取符合条件的数据

例1:提取一次不同内容

package com.example.a;
 
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
public class Demo {
    public static void main(String[] args) {
        String line = "This order was aabbcc placed for QT3000! OK?";
 
        String regex = "(\\D*)(\\s+)(aa\\S+)(\\D*)(\\d+)(.*)";
 
        // 创建 Pattern 对象
        Pattern pattern = Pattern.compile(regex);
 
        // 现在创建 matcher 对象
        Matcher m = pattern.matcher(line);
        if (m.find()) {
            System.out.println("group0: " + m.group(0));
            System.out.println("group1: " + m.group(1));
            System.out.println("group2: " + m.group(2));
            System.out.println("group3: " + m.group(3));
            System.out.println("group3: " + m.group(4));
            System.out.println("group3: " + m.group(5));
            System.out.println("group3: " + m.group(6));
        }
    }
}

----运行以上代码，将输出以下信息-----
group0: This order was aabbcc placed for QT3000! OK?
group1: This order was
group2:  
group3: aabbcc
group3:  placed for QT
group3: 3000
group3: ! OK?

例2:提取多次相同内容

package com.example.a;
 
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
public class Demo {
    public static void main(String[] args) {
        Pattern pattern = Pattern.compile("(LM\\d+)");
        String str = "张三[LM89652] 李四[LM12365] 王五[LM56856]";
        Matcher matcher = pattern.matcher(str);
        while (matcher.find()) {
            System.out.println(matcher.group(1));
        }
    }
}

-----运行以上代码，将输出以下信息----
LM89652
LM12365
LM56856
Matcher详解