Java内存释放实现代码案例

StringBuilder dada = null;
    for(int i=0; i<1000; i++){
      dada = new StringBuilder();
      for(int j=0; j<1000; j++){
        dada.append("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF");
      }
      
    }
    System.out.println("释放前");
    StringBuilder dada1 = new StringBuilder() ;
    dada1.append("1");
    dada = dada1;
    System.out.println("释放后");

StringBuilder dada = dada = new StringBuilder();;
    for(int i=0; i<1000; i++){
      for(int j=0; j<1000; j++){
        dada.append("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF");
      }
      
    }