Java 实例 - 连接字符串
以下实例演示了通过 "+" 操作符和StringBuffer.append() 方法来连接字符串,并比较其性能:
StringConcatenate.java 文件
public class StringConcatenate {
public static void main(String[] args){
long startTime = System.currentTimeMillis();
for(int i=0;i<5000;i++){
String result = "This is"
+ "testing the"
+ "difference"+ "between"
+ "String"+ "and"+ "StringBuffer";
}
long endTime = System.currentTimeMillis();
System.out.println("字符串连接"
+ " - 使用 + 操作符 : "
+ (endTime - startTime)+ " ms");
long startTime1 = System.currentTimeMillis();
for(int i=0;i<5000;i++){
StringBuffer result = new StringBuffer();
result.append("This is");
result.append("testing the");
result.append("difference");
result.append("between");
result.append("String");
result.append("and");
result.append("StringBuffer");
}
long endTime1 = System.currentTimeMillis();
System.out.println("字符串连接"
+ " - 使用 StringBuffer : "
+ (endTime1 - startTime1)+ " ms");
}
}
public class StringConcatenate {
public static void main(String[] args){
long startTime = System.currentTimeMillis();
for(int i=0;i<5000;i++){
String result = "This is"
+ "testing the"
+ "difference"+ "between"
+ "String"+ "and"+ "StringBuffer";
}
long endTime = System.currentTimeMillis();
System.out.println("字符串连接"
+ " - 使用 + 操作符 : "
+ (endTime - startTime)+ " ms");
long startTime1 = System.currentTimeMillis();
for(int i=0;i<5000;i++){
StringBuffer result = new StringBuffer();
result.append("This is");
result.append("testing the");
result.append("difference");
result.append("between");
result.append("String");
result.append("and");
result.append("StringBuffer");
}
long endTime1 = System.currentTimeMillis();
System.out.println("字符串连接"
+ " - 使用 StringBuffer : "
+ (endTime1 - startTime1)+ " ms");
}
}
以上代码实例输出结果为:
字符串连接 - 使用 + 操作符 : 0 ms
字符串连接 - 使用 StringBuffer : 6 ms