使用场景：用某个分隔符拼接字符串
- 下边是我使用过的几种方式
-
- 废话不多说，直接上代码
- 1.使用流
- 2.StringBuilder
- [3.StringJoiner(https://blog.csdn.net/qq_43417581/article/details/126076152?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522170478446616800186556680%2522%252C%2522scm%2522%253A%252220140713.130102334..%2522%257D\&request_id=170478446616800186556680\&biz_id=0\&utm_medium=distribute.pc_search_result.none-task-blog-2\~all\~sobaiduend\~default-2-126076152-null-null.142\^v99\^pc_search_result_base6\&utm_term=StringJoiner\&spm=1018.2226.3001.4187) （详情请点击，看的大佬的）](#3.StringJoiner （详情请点击，看的大佬的）)
- [4. Guava](#4. Guava)
- 做一个性能测试
下边是我使用过的几种方式
- 使用流
- StringBuilder
- StringJoiner
- Guava
当然，肯定要看业务场景来选择适当的方法，这里小编为大家做过性能测试。
废话不多说，直接上代码
初始数据
java
List<String> list = Arrays.asList("Luffy", "Zoro", "Nami",
"Usopp", "Sanji", "Chopper",
"Robin", "FRANKY", "BROOK");1.使用流
java
String result = list.stream().collect(Collectors.joining(","));2.StringBuilder
java
StringBuilder strBur = new StringBuilder();
list.forEach(val -> {
strBur.append(val).append(",");
});
strBur.toString();3.StringJoiner （详情请点击，看的大佬的）
java
StringJoiner strJor = new StringJoiner(",");
for(String str : list) {
strJor.add(str);
}
strJor.toString();4. Guava
java
String result = Joiner.on(",").join(list);做一个性能测试
java
package com.cck;
import java.util.Arrays;
import java.util.List;
import java.util.StringJoiner;
import java.util.function.Consumer;
import java.util.stream.Collectors;
import com.google.common.base.Joiner;
public class Test {
// 1.使用流
public static Consumer<List<String>> testStream() {
return (list) -> {
String result = list.stream().collect(Collectors.joining(","));
};
}
// 2.StringBuilder
public static Consumer<List<String>> testStringBuilder() {
return (list) -> {
StringBuilder strBur = new StringBuilder();
list.forEach(val -> {
strBur.append(val).append(",");
});
strBur.toString();
};
}
// 3.StringJoiner
public static Consumer<List<String>> testStringJoiner() {
return (list) -> {
StringJoiner strjor = new StringJoiner(",");
for(String str : list) {
strjor.add(str);
}
strjor.toString();
};
}
// 4.Guava
public static Consumer<List<String>> testGuava() {
return (list) -> {
String result = Joiner.on(",").join(list);
};
}
public static void test(Consumer<List<String>> consumer,
List<String> list, String msg) {
long start = System.currentTimeMillis();
for (int i = 0; i < 1000000; i++) {
consumer.accept(list);
}
long end = System.currentTimeMillis();
System.out.println(msg + " need time : " + (end - start));
}
public static void main(String[] args) {
List<String> list = Arrays.asList("Luffy", "Zoro", "Nami",
"Usopp", "Sanji", "Chopper",
"Robin", "FRANKY", "BROOK");
test(testStream(), list, "1.使用流");
test(testStringBuilder(), list, "2.StringBuilder");
test(testStringJoiner(), list, "3.StringJoiner");
test(testGuava(), list, "4.Guava");
}
} 执行10w次用时比较如下：
执行100w次用时比较如下：
感觉需要根据运算量去决定用哪种方法。
在没特别要求的情况下，自己还是使用Guava的多一些，因为看起来好看些。