Java字符串与文件的互转
Java中有时候需要读取一个文本类的文件,将其转换为字符串，然后做进一步处理。Java中没有现成的API方法，自己手动实现一个，大家来分享。
一、字符串转换为文件
/**
* 将字符串写入指定文件(当指定的父路径中文件夹不存在时，会最大限度去创建，以保证保存成功！)
*
* @param res 原字符串
* @param filePath 文件路径
* @return 成功标记
*/
public static boolean string2File(String res, String filePath) {
boolean flag = true;
BufferedReader bufferedReader = null;
BufferedWriter bufferedWriter = null;
try {
File distFile = new File(filePath);
if (!distFile.getParentFile().exists()) distFile.getParentFile().mkdirs();
bufferedReader = new BufferedReader( new StringReader(res));
bufferedWriter = new BufferedWriter( new FileWriter(distFile));
char buf[] = new char[1024]; //字符缓冲区
int len;
while ((len = bufferedReader.read(buf)) != -1) {
bufferedWriter.write(buf, 0, len);
}
bufferedWriter.flush();
bufferedReader.close();
bufferedWriter.close();
} catch (IOException e) {
e.printStackTrace();
flag = false;
return flag;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return flag;
}
* 将字符串写入指定文件(当指定的父路径中文件夹不存在时，会最大限度去创建，以保证保存成功！)
*
* @param res 原字符串
* @param filePath 文件路径
* @return 成功标记
*/
public static boolean string2File(String res, String filePath) {
boolean flag = true;
BufferedReader bufferedReader = null;
BufferedWriter bufferedWriter = null;
try {
File distFile = new File(filePath);
if (!distFile.getParentFile().exists()) distFile.getParentFile().mkdirs();
bufferedReader = new BufferedReader( new StringReader(res));
bufferedWriter = new BufferedWriter( new FileWriter(distFile));
char buf[] = new char[1024]; //字符缓冲区
int len;
while ((len = bufferedReader.read(buf)) != -1) {
bufferedWriter.write(buf, 0, len);
}
bufferedWriter.flush();
bufferedReader.close();
bufferedWriter.close();
} catch (IOException e) {
e.printStackTrace();
flag = false;
return flag;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return flag;
}
二、文件转换为字符串
/**
* 文本文件转换为指定编码的字符串
*
* @param file 文本文件
* @param encoding 编码类型
* @return 转换后的字符串
* @throws IOException
*/
public static String file2String(File file, String encoding) {
InputStreamReader reader = null;
StringWriter writer = new StringWriter();
try {
if (encoding == null || "".equals(encoding.trim())) {
reader = new InputStreamReader( new FileInputStream(file), encoding);
} else {
reader = new InputStreamReader( new FileInputStream(file));
}
//将输入流写入输出流
char[] buffer = new char[DEFAULT_BUFFER_SIZE];
int n = 0;
while (-1 != (n = reader.read(buffer))) {
writer.write(buffer, 0, n);
}
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
if (reader != null)
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
//返回转换结果
if (writer != null)
return writer.toString();
else return null;
}
* 文本文件转换为指定编码的字符串
*
* @param file 文本文件
* @param encoding 编码类型
* @return 转换后的字符串
* @throws IOException
*/
public static String file2String(File file, String encoding) {
InputStreamReader reader = null;
StringWriter writer = new StringWriter();
try {
if (encoding == null || "".equals(encoding.trim())) {
reader = new InputStreamReader( new FileInputStream(file), encoding);
} else {
reader = new InputStreamReader( new FileInputStream(file));
}
//将输入流写入输出流
char[] buffer = new char[DEFAULT_BUFFER_SIZE];
int n = 0;
while (-1 != (n = reader.read(buffer))) {
writer.write(buffer, 0, n);
}
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
if (reader != null)
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
//返回转换结果
if (writer != null)
return writer.toString();
else return null;
}
不想抛出太多的检查异常，如果你需要捕捉，就抛出吧。
注意：对于文件转换为字符串，存在一个编码问题。上面的file2String方法中，如果你不知道编码，调用时候方法设为null即可，此时使用系统默认的编码类型。
本文转自 leizhimin 51CTO博客，原文链接：http://blog.51cto.com/lavasoft/131928，如需转载请自行联系原作者
