java字符替换三个简单实例

java字符替换，在java中进行字符替换我们也可以用到replace函数，下面来看看三个实例的方法.

public class MainClass
{
   public static void main( String args[] )
   {
      String s1 = new String( "hello" );
      String s2 = new String( "GOODBYE" );
      String s3 = new String( "   spaces   " );

      System.out.printf( "s1 = %sns2 = %sns3 = %snn", s1, s2, s3 );

      // test method replace     
      System.out.printf("Replace 'l' with 'L' in s1: %snn", s1.replace( 'l', 'L' ) );

   } // end main
}

输出结果

s1 = hello
s2 = GOODBYE
s3 =    spaces  

Replace 'l' with 'L' in s1: heLLo

实例二

public class Main {
  public static void main(String[] argv) throws Exception {
    System.out.println(replace("this is a test", "is", "are"));
  }

  static String replace(String str, String pattern, String replace) {
    int start = 0;
    int index = 0;
    StringBuffer result = new StringBuffer();

    while ((index = str.indexOf(pattern, start)) >= 0) {
      result.append(str.substring(start, index));
      result.append(replace);
      start = index + pattern.length();
    }
    result.append(str.substring(start));
    return result.toString();
  }
}

看一个面试代码   java中用指定的字符串替换指定的字符串

public class StringReplacer
{
    private String str;

    public StringReplacer(String src, String before, String after) {
    str = replaceString(src, before, after);
    }

    public String toString() {
    return str;
    }

    public static String replaceString(String src,String before,String after) {
   StringBuffer sb = new StringBuffer();
   int oldidx = 0;
   int idx = src.indexOf(before);
   while (idx != -1) {
     sb.append(src.substring(oldidx, idx)).append(after);
     oldidx = idx + before.length();
     idx = src.indexOf(before, oldidx);
   }
   if (oldidx < src.length())
     sb.append(src.substring(oldidx));
   return sb.toString();
    }
}