java读取日志文件，增量添加内容到文件

系统管理员 2022-09-10 08:10 193阅读 0赞

# FileUtil类 #

package org.fiend.swing.test.filesync;
    
    import java.io.*;
    
    /**
     * @author pelang 2021-09-06 16:14:05
     */
    public class FileUtil {
        /**
         * 读取文件内容
         * @param fileName fileName
         * @return content
         */
        public static String readFileContent(String fileName) {
            File file = new File(fileName);
            BufferedReader reader = null;
            StringBuilder sbf = new StringBuilder();
            try {
                reader = new BufferedReader(new FileReader(file));
                String tempStr;
                while ((tempStr = reader.readLine()) != null) {
                    sbf.append(tempStr).append("\n");
                }
                reader.close();
    
                return sbf.toString();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (reader != null) {
                    try {
                        reader.close();
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                }
            }
            return sbf.toString();
        }
    
        /**
         * 向文件中追加内容
         * @param fileName fileName
         * @param content content
         */
        public static void appendFile(String fileName, String content) {
            BufferedWriter out = null;
            try {
                out = new BufferedWriter(new OutputStreamWriter(
                        new FileOutputStream(fileName, true)));
                out.write(content + "\r\n");
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    assert out != null;
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }