com.xiaoleilu.hutool.io.file.FileReader Maven / Gradle / Ivy
package com.xiaoleilu.hutool.io.file;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import com.xiaoleilu.hutool.io.FileUtil;
import com.xiaoleilu.hutool.io.IORuntimeException;
import com.xiaoleilu.hutool.io.IoUtil;
import com.xiaoleilu.hutool.io.LineHandler;
import com.xiaoleilu.hutool.util.CharsetUtil;
import com.xiaoleilu.hutool.util.StrUtil;
/**
* 文件读取器
*
* @author Looly
*
*/
public class FileReader extends FileWrapper {
/**
* 创建 FileReader
* @param file 文件
* @param charset 编码，使用 {@link CharsetUtil}
* @return {@link FileReader}
*/
public static FileReader create(File file, Charset charset){
return new FileReader(file, charset);
}
/**
* 创建 FileReader, 编码：{@link FileWrapper#DEFAULT_CHARSET}
* @param file 文件
* @return {@link FileReader}
*/
public static FileReader create(File file){
return new FileReader(file);
}
// ------------------------------------------------------- Constructor start
/**
* 构造
* @param file 文件
* @param charset 编码，使用 {@link CharsetUtil}
*/
public FileReader(File file, Charset charset) {
super(file, charset);
checkFile();
}
/**
* 构造
* @param file 文件
* @param charset 编码，使用 {@link CharsetUtil#charset(String)}
*/
public FileReader(File file, String charset) {
this(file, CharsetUtil.charset(charset));
}
/**
* 构造
* @param filePath 文件路径，相对路径会被转换为相对于ClassPath的路径
* @param charset 编码，使用 {@link CharsetUtil}
*/
public FileReader(String filePath, Charset charset) {
this(FileUtil.file(filePath), charset);
}
/**
* 构造
* @param filePath 文件路径，相对路径会被转换为相对于ClassPath的路径
* @param charset 编码，使用 {@link CharsetUtil#charset(String)}
*/
public FileReader(String filePath, String charset) {
this(FileUtil.file(filePath), CharsetUtil.charset(charset));
}
/**
* 构造
* 编码使用 {@link FileWrapper#DEFAULT_CHARSET}
* @param file 文件
*/
public FileReader(File file) {
this(file, DEFAULT_CHARSET);
}
/**
* 构造
* 编码使用 {@link FileWrapper#DEFAULT_CHARSET}
* @param filePath 文件路径，相对路径会被转换为相对于ClassPath的路径
*/
public FileReader(String filePath) {
this(filePath, DEFAULT_CHARSET);
}
// ------------------------------------------------------- Constructor end
/**
* 读取文件所有数据
* 文件的长度不能超过 {@link Integer#MAX_VALUE}
*
* @return 字节码
* @throws IORuntimeException IO异常
*/
public byte[] readBytes() throws IORuntimeException {
long len = file.length();
if (len >= Integer.MAX_VALUE) {
throw new IORuntimeException("File is larger then max array size");
}
byte[] bytes = new byte[(int) len];
FileInputStream in = null;
int readLength;
try {
in = new FileInputStream(file);
readLength = in.read(bytes);
if(readLength < len){
throw new IOException(StrUtil.format("File length is [{}] but read [{}]!", len, readLength));
}
} catch (Exception e) {
throw new IORuntimeException(e);
} finally {
IoUtil.close(in);
}
return bytes;
}
/**
* 读取文件内容
*
* @return 内容
* @throws IORuntimeException IO异常
*/
public String readString() throws IORuntimeException{
return new String(readBytes(), this.charset);
}
/**
* 从文件中读取每一行数据
*
* @param 集合类型
* @param collection 集合
* @return 文件中的每行内容的集合
* @throws IORuntimeException IO异常
*/
public > T readLines(T collection) throws IORuntimeException {
BufferedReader reader = null;
try {
reader = FileUtil.getReader(file, charset);
String line;
while (true) {
line = reader.readLine();
if (line == null) {
break;
}
collection.add(line);
}
return collection;
} catch (IOException e) {
throw new IORuntimeException(e);
} finally {
IoUtil.close(reader);
}
}
/**
* 按照行处理文件内容
*
* @param lineHandler 行处理器
* @throws IORuntimeException IO异常
* @since 3.0.9
*/
public void readLines(LineHandler lineHandler) throws IORuntimeException{
BufferedReader reader = null;
try {
reader = FileUtil.getReader(file, charset);
IoUtil.readLines(reader, lineHandler);
} finally {
IoUtil.close(reader);
}
}
/**
* 从文件中读取每一行数据
*
* @return 文件中的每行内容的集合
* @throws IORuntimeException IO异常
*/
public List readLines() throws IORuntimeException {
return readLines(new ArrayList());
}
/**
* 按照给定的readerHandler读取文件中的数据
*
* @param 读取的结果对象类型
* @param readerHandler Reader处理类
* @return 从文件中read出的数据
* @throws IORuntimeException IO异常
*/
public T read(ReaderHandler readerHandler) throws IORuntimeException {
BufferedReader reader = null;
T result = null;
try {
reader = FileUtil.getReader(this.file, charset);
result = readerHandler.handle(reader);
} catch (IOException e) {
throw new IORuntimeException(e);
} finally {
IoUtil.close(reader);
}
return result;
}
/**
* 获得一个文件读取器
*
* @return BufferedReader对象
* @throws IORuntimeException IO异常
*/
public BufferedReader getReader() throws IORuntimeException {
return IoUtil.getReader(getInputStream(), this.charset);
}
/**
* 获得输入流
*
* @return 输入流
* @throws IORuntimeException IO异常
*/
public BufferedInputStream getInputStream() throws IORuntimeException {
try {
return new BufferedInputStream(new FileInputStream(this.file));
} catch (IOException e) {
throw new IORuntimeException(e);
}
}
/**
* 将文件写入流中
*
* @param out 流
* @return File
* @throws IORuntimeException IO异常
*/
public File writeToStream(OutputStream out) throws IORuntimeException {
FileInputStream in = null;
try {
in = new FileInputStream(file);
IoUtil.copy(in, out);
}catch (IOException e) {
throw new IORuntimeException(e);
} finally {
IoUtil.close(in);
}
return this.file;
}
// -------------------------------------------------------------------------- Interface start
/**
* Reader处理接口
*
* @author Luxiaolei
*
* @param Reader处理返回结果类型
*/
public interface ReaderHandler {
public T handle(BufferedReader reader) throws IOException;
}
// -------------------------------------------------------------------------- Interface end
/**
* 检查文件
*
* @throws IORuntimeException IO异常
*/
private void checkFile() throws IORuntimeException {
if (false == file.exists()) {
throw new IORuntimeException("File not exist: " + file);
}
if (false == file.isFile()) {
throw new IORuntimeException("Not a file:" + file);
}
}
}