public class Test {

    public static int a, b, c;

    public static void main(String arg[]) throws IOException {
        try {
            BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
            System.out.println("输入三边值，每个值输入后回车");
            System.out.println("请输入:");
            a = Integer.valueOf(stdin.readLine());
            b = Integer.valueOf(stdin.readLine());
            c = Integer.valueOf(stdin.readLine());
            checkTriangle(a,b,c);
        }
        catch (IOException e) {
            System.out.println("出现异常!");
            System.exit(0);
        }
    }
    public static void checkTriangle(int a,int b,int c){
        if (a + b < c || a + c < b || b + c < a) {
            System.out.println("你输入的不能构成三角形");
        }
        if (a == b || a == c || b == c) {
            if (a == b && b == c)
                System.out.println("等边三角形");
            else
                System.out.println("等腰三角形");
        }
        else {
            System.out.println("一般三角形");
        }
        
        if(a+b+c>30) {
            System.out.println("三角形周长是" +(a+b+c));
        }else {
            System.out.println("三角形三边长分别是：" + a + " " + b + " " + c);
        }
    }
}

------解决方案--------------------

Java code

package com.test;

import java.util.Scanner;

public class Triangle {
    int a , b , c;
    public Triangle(int a , int b , int c){
        this.a = a;
        this.b = b;
        this.c = c;
    }
    
    //是否为三角形（两边之和大于第三边，之差小于第三边）
    public boolean isTri(){
        return  a + b > c && Math.abs(a - b) < c;
    }
    
    //是否为等边三角形（三边相等）
    public boolean isEquilateralTri(){
        return a == b && b == c; //
    }
    
    //是否为等腰三角形(两边相等)
    public boolean isIsoscelesTri(){
        return a == b || b == c;
    }
    
    //是否为一般三角形（三边都不相等）
    public boolean isGeneralTri(){
        return a != b && b != c;
    }
    
    public static void main(String[] args) {
        int a = 0, b = 0 , c = 0;
        System.out.println("*********请输入三条边值,每个值输入后回车********");
        Scanner can = new Scanner(System.in);
        System.out.print("第一条边：");
        a = can.nextInt();
        System.out.print("第二条边：");
        b = can.nextInt();
        System.out.print("第三条边：");
        c = can.nextInt();
        Triangle tri = new Triangle(a ,b, c);
        if(tri.isTri()){
            System.out.println("******你输入的是个三角形******");
            if(tri.isEquilateralTri()){
                System.out.println("你输入的三条边为："+a+" "+b+" "+c+"   为等边三角形");
            }else if(tri.isIsoscelesTri()){
                System.out.println("你输入的三条边为："+a+" "+b+" "+c+"   为等腰三角形");
            }else if(tri.isGeneralTri()){
                System.out.println("你输入的三条边为："+a+" "+b+" "+c+"   为一般三角形");
            }
        }else{
            System.out.println("******你输入的不是三角形******");
        }
    }

}