你这个程序没错误 ，不过是输出的格式不正确，你看看我改的
import java.util.Scanner;
public class Sum {
    int k;
    public Sum(int m)
    {
        for(int i=1;i<m/2;i++)
        {
            int sum=0;
            for(int j=i;j<m/2;j++)
                {
                    sum+=j;
                    if(sum==m)
                    {
                        System.out.print(m+"=");
                        for( k=i;k<j;k++)//修改的就是这个循环
                            {
                                
                                System.out.print(k+"+");
                                
                            }
                        System.out.print(k);
                        break;
                    }
                    if(sum>m)
                        break;
                }
            System.out.println();
            
        }
        
    }
    public static void main(String[] args)
    {
        Scanner in=new Scanner(System.in);
        System.out.println("请输入整数");
        int b=in.nextInt();
        new Sum(b);
        
        
    }

}

这个程序  功能不全吧。