add FileUtils

pom.xml

@@ -8,6 +8,14 @@
     <artifactId>CodeSnippet</artifactId>
     <version>1.0-SNAPSHOT</version>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.3.1</version>
+        </dependency>
+    </dependencies>
+
     <properties>
         <maven.compiler.source>8</maven.compiler.source>
         <maven.compiler.target>8</maven.compiler.target>

src/main/java/com/github/aborn/tools/StringTools.java

@@ -1,5 +1,7 @@
 package com.github.aborn.tools;
 
+import com.github.aborn.utils.FileUtils;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -35,12 +37,14 @@ public class StringTools {
 
     /**
      * 对邮件里的内容获取
-     * TODO 从文件中读取内容
-     *
      * @param args
      */
     public static void main(String[] args) {
         String inputValue = "zhangsan <zhangsan@qq.com>; lisi <lisi@hotmail.com>; ";
+        String fileName = "/Users/aborn/temp/t.txt";
+        String fileContent = FileUtils.read(fileName);
         System.out.println(getEmailNameInfo(inputValue));
+        System.out.println("\n");
+        System.out.println(getEmailNameInfo(fileContent));
     }
 }

src/main/java/com/github/aborn/utils/FileUtils.java

@@ -0,0 +1,65 @@
+package com.github.aborn.utils;
+
+import java.io.*;
+
+import org.apache.commons.lang3.StringUtils;
+
+/**
+ * @author aborn
+ * @date 2021/06/30 11:43 AM
+ */
+public class FileUtils {
+
+    public static void main(String[] args) {
+        String file = "/Users/aborn/temp/t.txt";
+        System.out.println(read(file));
+    }
+
+    /**
+     * Read file content as string，
+     * null if file doesn't exist or read exception
+     *
+     * @param fileName 文件名全路径
+     * @return file content
+     */
+    public static String read(String fileName) {
+        if (StringUtils.isBlank(fileName)) {
+            return null;
+        }
+
+        File file = new File(fileName);
+        if (!file.exists()) {
+            return null;
+        }
+
+        // 再从文件里读
+        InputStream inputStream = null;
+        try {
+            inputStream = new FileInputStream(file);
+            // 临时存储 bitSet的 array信息
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+
+            // 缓冲区大小
+            int bufferSize = 1024;
+            byte[] buffer = new byte[bufferSize];
+            int n;
+            // 读取到buffer缓冲区，缓冲区大小为bufferSize
+            while ((n = inputStream.read(buffer)) != -1) {
+                out.write(buffer, 0, n);
+            }
+
+            return out.toString();
+        } catch (IOException e) {
+            e.printStackTrace();
+            return null;
+        } finally {
+            if (inputStream != null) {
+                try {
+                    inputStream.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+}