線程“主”java.lang.RuntimeException 中的錯誤異常

Question

我試圖修復錯誤，但它總是返回此異常，並且在嘗試處理時異常仍然出錯

終端異常

    $  /usr/bin/env c:\\Users\\lolo2\\.vscode\\extensions\\vscjava.vscode-java-debug-0.34.0\\scripts\\launcher.bat "C:\\Program Files\\Java\\jdk-15.0.2\\bin\\java.exe" -XX:+ShowCodeDetailsInExceptionMessages -Dfile.encoding=UTF-8 @C:\\Users\\lolo2\\AppData\\Local\\Temp\\cp_60g01ctldkies4ai3k17s3gfy.argfile br.com.efipee.exceptions.AlunosMain 
Aluno 1
Aluna 2
Aluno 3
Aluno 4
Aluno 5
Palavra 6
Exception in thread "main" java.lang.RuntimeException: Arquivo não encontrado   
        at br.com.efipee.exceptions.AlunoService.findAll(AlunoService.java:44)  
        at br.com.efipee.exceptions.AlunoService.findAluno(AlunoService.java:49)
        at br.com.efipee.exceptions.AlunosMain.main(AlunosMain.java:7)

AlunosMain.java

package br.com.efipee.exceptions;

public class AlunosMain {

    public static void main(String[] args) {
        try {
            new AlunoService().findAluno("Palavra 6");
        } catch (AlunoNaoExisteException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

AlunoService.java

package br.com.efipee.exceptions;

import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.Scanner;

public class AlunoService {
    
    
    public List<String> findAll() {
        // recebendo caminho arquivo
        File file = new File("C:\\Users\\lolo2\\OneDrive\\Documentos\\JavaPro\\Modulo\\exceptions\\target\\classes\\alunos.txt");
        //C:\\Users\\lolo2\\OneDrive\\Documentos\\JavaPro\\Modulo\\exceptions\\target\\classes\\


        //instanciando Scanner
        Scanner sc = null;

        // tratamento errro
        try {

            // lendo arquivo
            sc = new Scanner(file);

            // procurando linhas

            while (sc.hasNextLine()) {

                // imprimindo linhas
                System.out.println(sc.nextLine());
            }// try
        } catch (IOException e) {
            System.out.println("Error: " + e.getMessage());
        }//cath

        // fechando Scanner
        finally {
            if(sc != null){
                sc.close();
            }//if

        }//finally
        throw new RuntimeException("Arquivo não encontrado");
    }// findAll

    
    public String findAluno(String nome) throws AlunoNaoExisteException{
        return findAll().stream()
            .filter(aluno -> aluno.equals(nome))
            .findFirst()
            .orElseThrow(() -> new AlunoNaoExisteException(nome));

    }
}// class

這個之前的代碼也有問題。

舊 AlunoService.java

public List<String> findAlll(){
    String caminho = AlunoService.class.getClassLoader()
    .getResource("alunos.txt")
    .getPath();

    try{
        List<String> alunos = Files.readAllLines(Path.of(caminho));
        return alunos;
    }catch(IOException ioException){
        return Collections.emptyList();
    }

控制台上返回以下內容：“Illegal char <:> at index 2:”

Answer 1

當您執行findAll().stream()時，“findAll”方法需要非異常完成。

沒有返回列表的代碼路徑？

而不是throw new RuntimeException(...); 利用

throw new AlunoNaoExisteException(...)

那么它應該被抓住。 或者捕獲一個 RuntimeException。

也許你想修復findAll

public List<String> findAll() {
    List<String> results = new ArrayList<>();
    ... //your code
        // replace this
        //System.out.println(sc.nextLine());
        //with this.
        results.add(sc.nextLine());
    ... //finish.
    return results;
}