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feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
/*
* Copyright (C) 2008 feilong
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.feilong.io;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UncheckedIOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.feilong.core.CharsetType;
import com.feilong.core.Validate;
import com.feilong.core.lang.StringUtil;
import com.feilong.lib.io.IOUtils;
import com.feilong.lib.springframework.core.io.DefaultResourceLoader;
import com.feilong.lib.springframework.core.io.Resource;
import com.feilong.lib.springframework.core.io.ResourceLoader;
/**
* {@link java.io.InputStream} 工具类.
*
* @author feilong
* @see ReaderUtil
* @see java.io.InputStream
* @since 1.0.9
*/
@SuppressWarnings("squid:S1192") //String literals should not be duplicated
public final class InputStreamUtil{
/** The Constant LOGGER. */
private static final Logger LOGGER = LoggerFactory.getLogger(InputStreamUtil.class);
/** Don't let anyone instantiate this class. */
private InputStreamUtil(){
//AssertionError不是必须的. 但它可以避免不小心在类的内部调用构造器. 保证该类在任何情况下都不会被实例化.
//see 《Effective Java》 2nd
throw new AssertionError("No " + getClass().getName() + " instances for you!");
}
//---------------------------------------------------------------
/**
* Return a Resource handle for the 指定的资源路径.
*
*
* The handle should always be a reusable resource descriptor,allowing for multiple {@link Resource#getInputStream()} calls.
*
*
* Note that a Resource handle does not imply an existing resource; you need to invoke {@link Resource#exists} to check for existence.
*
* @param location
*
* - 支持全路径, 比如. "file:C:/test.dat".
* - 支持classpath 伪路径, e.g. "classpath:test.dat".
* - 支持相对路径, e.g. "WEB-INF/test.dat".
* - 如果上述都找不到,会再次转成FileInputStream,比如 "/Users/feilong/feilong-io/src/test/resources/readFileToString.txt"
*
* @return the input stream
* @since 3.0.0
*/
public static InputStream getInputStream(String location){
ResourceLoader resourceLoader = new DefaultResourceLoader();
Resource resource = resourceLoader.getResource(location);
try{
return resource.getInputStream();
}catch (FileNotFoundException e){
//class path resource [Users/feilong/workspace/feilong/feilong/feilong-io/src/test/resources/readFileToString.txt] cannot be opened because it does not exist
LOGGER.warn(
"[{}] use DefaultResourceLoader not found,will convert to FileInputStream.Suggest you try use [file://] or [classpath:] to improve the parse speed",
location);
return FileUtil.getFileInputStream(location);
}catch (IOException e){
throw new UncheckedIOException("location:[" + location + "]", e);
}
}
//---------------------------------------------------------------
/**
* 构造一个 {@link ByteArrayInputStream}.
*
* @param str
* the str
* @param charsetType
* 受支持的 charset 名称,比如 utf-8, {@link CharsetType}
* @return 如果 str 是null,抛出 {@link NullPointerException}
* @see "org.apache.commons.io.IOUtils#toInputStream(String, Charset)"
* @since 1.12.1
*/
public static InputStream newByteArrayInputStream(String str,String charsetType){
Validate.notNull(str, "str can't be null!");
return new ByteArrayInputStream(StringUtil.getBytes(str, charsetType));
}
//---------------------------------------------------------------
/**
* 使用默认的编码集 {@link Charset#defaultCharset()} 将 {@link java.io.InputStream} 转成string.
*
*
* 如果需要将 {@link String} 转成 {@link InputStream} 可以调用 {@link IOUtils#toInputStream(String, Charset)}
*
*
* @param inputStream
* the input stream
* @return 将 {@link java.io.InputStream} 转成string
* 如果 inputStream 是null,抛出 {@link NullPointerException}
* @see #toString(InputStream, String)
*/
public static String toString(InputStream inputStream){
Validate.notNull(inputStream, "inputStream can't be null!");
Charset defaultCharset = Charset.defaultCharset();
String charsetName = defaultCharset.name();
LOGGER.debug("will use defaultCharset:[{}]", charsetName);
return toString(inputStream, charsetName);
}
/**
* 将 {@link java.io.InputStream} 转成string.
*
*
* 读取cmd命令结果时候, 有时候读取的是乱码,需要传递 charsetName字符集.
*
*
*
* 如果需要将 {@link String} 转成 {@link InputStream} 可以调用 {@link IOUtils#toInputStream(String, Charset)}
*
*
* @param inputStream
* the input stream
* @param charsetName
* 指定受支持的 charset 的名称
* @return 将 {@link java.io.InputStream} 转成string
* 如果 inputStream 是null,抛出 {@link NullPointerException}
* @see #toBufferedReader(InputStream, String)
* @see ReaderUtil#toString(Reader)
*/
public static String toString(InputStream inputStream,String charsetName){
Validate.notNull(inputStream, "inputStream can't be null!");
Reader reader = toBufferedReader(inputStream, charsetName);
return ReaderUtil.toString(reader);
}
//---------------------------------------------------------------
/**
* 将 {@link java.io.InputStream} 转成 {@link java.io.BufferedReader} ({@link java.io.BufferedReader} 缓冲 高效读取).
*
* @param inputStream
* the input stream
* @param charsetName
* the charset name
* @return 如果 inputStream 是null,抛出 {@link NullPointerException}
* @see java.io.BufferedReader
* @see java.io.InputStreamReader#InputStreamReader(InputStream, String)
* @see com.feilong.lib.io.IOUtils#toBufferedReader(Reader)
*/
// 返回 BufferedReader , 方便调用者使用 BufferedReader readLine功能
public static BufferedReader toBufferedReader(InputStream inputStream,String charsetName){
Validate.notNull(inputStream, "inputStream can't be null!");
try{
Reader reader = new InputStreamReader(inputStream, charsetName);
// 缓冲 高效读取 bufferedReader
// 包装所有其 read() 操作可能开销很高的 Reader(如 FileReader 和 InputStreamReader).
return IOUtils.toBufferedReader(reader);
}catch (UnsupportedEncodingException e){
throw new UncheckedIOException(e);
}
}
}