文件输入流输出流

1，创建文件

public static File createFile(String fileName) {
    File file = new File(fileName);//fileName是file路径，如String writeFilePath = "F:\\clpsmart\\clp.ldif";
    try {
if (!file.exists()) {
            file.createNewFile();
        }
        StringBuilder strBuilder = new StringBuilder();
        strBuilder.append("dn: ou=infocenter,dc=gionee,dc=com"+"\r\n");
        strBuilder.append("objectClass: top"+"\r\n");
        strBuilder.append("objectClass: organizationalUnit"+"\r\n");
        strBuilder.append("ou: infocenter"+"\r\n");
        strBuilder.append("\r\n");
        FileOutputStream o = new FileOutputStream(fileName);
        o.write(strBuilder.toString().getBytes());
        o.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
return file;
}

2，读取文件

public static void readTxtFile(String filePath, File fileName) {
try {
        String encoding = "GBK";
        File file = new File(filePath);
        if (file.isFile() && file.exists()) { //判断文件是否存在
            InputStreamReader read = new InputStreamReader(
new FileInputStream(file), encoding);//考虑到编码格式
            BufferedReader bufferedReader = new BufferedReader(read);
            String lineTxt = null;
            Random random = new Random();
            while ((lineTxt = bufferedReader.readLine()) != null) {
                String[] str = lineTxt.split("[\\p{Space}]+");
                StringBuilder strBuilder = new StringBuilder();
                strBuilder.append("dn: uid="+str[2]+",ou=infocenter,dc=gionee,dc=com"+"\r\n");
                strBuilder.append("objectClass: posixAccount"+"\r\n");
                strBuilder.append("objectClass: top"+"\r\n");
                strBuilder.append("objectClass: inetOrgPerson"+"\r\n");
                strBuilder.append("gidNumber: 0"+"\r\n");
                String strUtfsn = "";
                String strUtfcn = "";
                for (int i = 0; i < str[1].length(); i++) {
                    strUtfsn = str[1].substring(0, 1);
                    strUtfcn  += str[1].substring(i, i+1);
                }
                BASE64Encoder b = new BASE64Encoder();
                strBuilder.append("sn::"+b.encode(strUtfsn.getBytes())+"\r\n");
                strBuilder.append("displayName::"+b.encode(strUtfcn.getBytes())+"\r\n");
                strBuilder.append("uid:"+str[2]+"\r\n");
                strBuilder.append("homeDirectory: /"+"\r\n");
                strBuilder.append("mail:"+str[3]+"\r\n");
                strBuilder.append("cn::"+b.encode(strUtfcn.getBytes())+"\r\n");
                strBuilder.append("uidNumber:"+Math.abs(random.nextInt())+ "\r\n");
                strBuilder.append("userPassword: 123456"+"\r\n");
                strBuilder.append("\r\n");
                writeFile(strBuilder, fileName);
            }
            read.close();
        } else {
            System.out.println("找不到指定的文件");
        }
    } catch (Exception e) {
        System.out.println("读取文件内容出错");
        e.printStackTrace();
    }
}

3，写入文件

public static void writeFile(StringBuilder content, File fileName) throws Exception {
    FileOutputStream o = null;
    try {
        o = new FileOutputStream(fileName, true);
        OutputStreamWriter out = new OutputStreamWriter(o, "UTF-8");
        BufferedWriter bufw = new BufferedWriter(out);//缓冲
        bufw.write(content.toString());
        bufw.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

这里输出的是ldap的ldif文件，注意ldif文件中的数据行不能有空格。