Java 我想问一下'；就这样，每当我尝试运行它时，它总是给我这样的运行时错误

我希望用户输入以下模式的行数，所以请标记我的错误。因为我是java初学者，所以请也给我推荐一些书。 必须显示此模式

**********   
*********    
********     
*******      
******       
*****        
****         
***          
**           
* 

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

这是一个代码：

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

import java.util.Scanner；
阶级模式{
公共静态void main（字符串agrs[]）{
int n；
扫描仪输入=新扫描仪（系统输入）；
System.out.println（“输入模式中的行数”）；
n=in.nextInt（）；
{
对于（int i=0；i如果您在oracle站点上检查，则异常的解释为：

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

由扫描程序引发，以指示检索到的令牌不存在
匹配所需类型的模式，或者标记已过期
所需类型的范围

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

输入非整数输入时引发此异常

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

您需要添加一个try/catch来捕获此信息，并通知用户输入错误

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

示例：

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

import java.util.Scanner;

public class PatternTest {
    public static void main(String agrs[]) {

        int n = -1;     

        do
        {
            try {
                Scanner in = new Scanner(System.in);    
                System.out.println("enter the no. of rows in the pattern");
                n = in.nextInt();               
            } catch (java.util.InputMismatchException e) {
                System.err.print("Please enter only an integer.");
            }
        }while(n == -1);

        for (int i = 0; i < n; i++) {
            for (int j = 0; j <= i; j++)
            System.out.print(" * ");
            System.out.println(" ");
        }

    }
}

import java.util.Scanner；
公共类模式测试{
公共静态void main（字符串agrs[]）{
int n=-1；
做
{
试一试{
扫描仪输入=新扫描仪（系统输入）；
System.out.println（“输入模式中的行数”）；
n=in.nextInt（）；
}catch（java.util.InputMismatchException e）{
System.err.print（“请只输入一个整数。”）；
}
}而（n==-1）；
对于（int i=0；i
试着看一下。这里很清楚
将下一个标记作为长标记返回。如果下一个标记不是浮点或超出范围，则引发InputMismatchException

import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)

请参阅。
但这只是表明存在错误，并没有给出最佳输出。@ashish您最初的问题集中在错误上。无论如何，更新包括输出。谢谢您的帮助。
import java.util.Scanner;
class pattern{
public static void main (String agrs[]){

int n;
Scanner in =new Scanner(System.in);
System.out.println("enter the no. of rows in the pattern");
n= in.nextInt();
{
for(int i=0;i<n;i++)
{   for(int j=0; j<=i;j++)

System.out.print(" * ");
System.out.println(" ");
}}
}}

  ERROR   ...... 
 enter the no. of rows in the pattern
 Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at pattern.main(pattern.java:8)