当用户输入字符串时，按下输入时没有任何反应

Question

我正在研究一个允许用户存储，借用和返回技术手册的库应用程序。

构建应用程序的返回部分时，我遇到了问题。

目前，如果用户借用手册并希望返回它，则必须从显示的借用手册列表中输入手册的标题。但是，如果用户希望在该列表中的第一个之后返回任何手册，则什么都不会发生。用户输入名称并点击回车键，但应用程序停止。

这里是我的描述错误的例子：

下面是相关代码：

static void returnManual(){ 
    System.out.printf("\n\nHere are the Manual/s currently out on loan:\n\n"); 
    if(ManualList.get(ManualChoice).status.equalsIgnoreCase(status2) && borrowedManuals.size() >= ManualChoice){ 
     for (int i = 0; i < borrowedManuals.size(); i++) 
      System.out.println(borrowedManuals.get(i).displayManual()); 
     returnManualTitle = Console.readString(Messages.enterManualTitle, Messages.tooShortMessage, 3); 
    } 

    int x = 0; 
    boolean titleExistance = false; 
    while (x < ManualList.size()){//Search for the Manual by title, if it exists change it's status, 
           //it's borrower and borrowDate. 

     if (ManualList.get(x).title.equalsIgnoreCase(returnManualTitle)){ 

      ManualList.get(x).status = "Available"; 
      ManualList.get(x).borrower = "N/A"; 
      ManualList.get(x).borrowDate = "N/A"; 
      ManualList.get(x).returnDate = "N/A"; 

      int p = 0; 
      borrowLoop: 
      while (p < borrowedManuals.size()){//Search for the Manual by title, if it exists change it's status, 
       //it's borrower and borrowDate. 

       if (borrowedManuals.get(p).title.equalsIgnoreCase(returnManualTitle)){ 

        borrowedManuals.remove(p); 
        break borrowLoop; 
       } 

      }    
      System.out.println(Messages.successReturnMessage); 
      titleExistance = true; 

      break;//if a title is found, break out of the loop and display choice menu. 
     } 
     x = x+1; 
    }//end of while loop. 
    if(titleExistance == false){ 
     boolean repeatReturnManual = Console.readYesNo("\n--------------------------------------------------------------------------" + "\n\nThe Manual with the title "+"\""+returnManualTitle +"\""+ " wasn't found!" 
                 +"\n\nDo you want to try again? (Y/N):\n"); 
     System.out.println("\n--------------------------------------------------------------------------"); 
     if(repeatReturnManual){ 
      returnManual(); 
     }else{ 
      Menu.displayMenu(); 
     } 
    }else if(titleExistance){ 
     Menu.menuChoice = 7; 
    }    
} 

/** 
* Removes the Manual. 
*/ 

Answer 1

borrowsManual while循环中的p需要递增，否则它将运行在无尽的lopp中。

while (p < borrowedManuals.size()) { 
    Manual borrowed = borrowedManuals.get(p); // guessing the name of this class 
    if (borrowed.title.equalsIgnoreCase(returnManualTitle)) { 
     borrowedManuals.remove(p); 
     break; 
    } 
    p++; // this is mising 
}   

（我不知道这整个线性搜索业务的那么好，但我们不希望重写整个应用程序，对不对？:)

Answer 2

你的方法不正确的返回类型。将返回类型更改为String，并将该行与Console.readString（）放在for循环之外。希望有所帮助！