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package w7; |
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import java.io.BufferedReader; |
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import java.io.FileReader; |
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public class RawCode { |
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public static void main(String[] args) { |
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int sum = 0; |
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// 1. 资源未自动关闭(若中间抛异常,br.close()不会执行)
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BufferedReader br = new BufferedReader(new FileReader("scores.txt")); |
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String line; |
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while ((line = br.readLine()) != null) { |
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// 2. 无数字格式异常处理(若行不是整数,直接崩溃)
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sum += Integer.parseInt(line); |
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} |
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// 3. 无IO异常处理(文件不存在/读取错误时直接崩溃)
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br.close(); |
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} |
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} |
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package w7; |
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import java.io.BufferedReader; |
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import java.io.FileReader; |
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import java.io.IOException; |
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import java.io.FileNotFoundException; |
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public class yichang { |
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public static void main(String[] args) { |
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int sum = 0; |
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int validCount = 0; // 记录有效分数的数量(避免除以0)
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// 🔵 核心改进1:try-with-resources 自动关闭资源
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try (BufferedReader br = new BufferedReader(new FileReader("scores.txt"))) { |
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String line; |
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int lineNumber = 0; // 记录当前行号(用于错误提示)
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while ((line = br.readLine()) != null) { |
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lineNumber++; |
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try { |
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// 尝试将行内容转为整数(处理数字格式错误)
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int score = Integer.parseInt(line); |
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sum += score; |
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validCount++; |
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} catch (NumberFormatException e) { |
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// 🔵 核心改进2:处理“数字格式错误”
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System.err.printf("第%d行的分数格式无效:%s%n", lineNumber, line); |
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} |
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} |
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} catch (FileNotFoundException e) { |
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// 🔵 核心改进2:处理“文件不存在”
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System.err.println("错误:成绩文件 scores.txt 不存在!请检查路径~"); |
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e.printStackTrace(); // 打印堆栈跟踪,辅助调试
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} catch (IOException e) { |
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// 🔵 核心改进2:处理“读取IO错误”(如权限不足、磁盘故障等)
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System.err.println("错误:读取成绩文件时发生IO异常!"); |
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e.printStackTrace(); |
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} |
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// 输出平均分(仅当有有效数据时计算)
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if (validCount > 0) { |
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double average = (double) sum / validCount; |
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System.out.printf("成绩的平均分是:%.2f%n", average); |
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} else { |
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System.out.println("没有有效的分数记录,无法计算平均分~"); |
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} |
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} |
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} |
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After Width: | Height: | Size: 19 KiB |
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After Width: | Height: | Size: 134 KiB |
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