java file to inputstream以及New Document From InputStream读取和写入文件操作实例代码

A. http://www.java2s.com/Code/Java/XML/NewDocumentFromInputStream.htm

New Document From InputStream

    

import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.io.StringWriter;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

/*******************************************************************************
 * Copyright (C) 2007 Google Inc.
 * 
 * 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.
 ******************************************************************************/

/**
 * Various XML utilities.
 * 
 * @author simonjsmith, ksim
 * @version 1.1 - ksim - March 6th, 2007 - Added functions regarding streaming
 * @version 1.2 - ksim - March 10th, 2007 - Added functions regarding DOM
 *          manipulation
 */
public class Utils {
  public static Document newDocumentFromInputStream(InputStream in) {
    DocumentBuilderFactory factory = null;
    DocumentBuilder builder = null;
    Document ret = null;

    try {
      factory = DocumentBuilderFactory.newInstance();
      builder = factory.newDocumentBuilder();
    } catch (ParserConfigurationException e) {
      e.printStackTrace();
    }

    try {
      ret = builder.parse(new InputSource(in));
    } catch (SAXException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
    return ret;
  }

}

B. http://www.zuidaima.com/share/1758442014903296.htm

java通过InputStream读取和写入文件操作实例代码

1. File to InputStream

1 File file = new File("file.xml");
2 InputStream inputStream = new FileInputStream(file);

2.InputStream to File

01 InputStream inputStream = new FileInputStream("file.xml");
02
03 OutputStream  outputStream = new FileOutputStream("file-new.xml");
04
05 int bytesWritten = 0;
06 int byteCount = 0;
07
08 byte[] bytes = new byte[1024];
09
10 while ((byteCount = inputStream.read(bytes)) != -1)
11 {
12           outputStream.write(bytes, bytesWritten, byteCount);
13            bytesWritten += byteCount;
14 }
15 inputStream.close();
16 outputStream.close();

项目截图

C. http://stackoverflow.com/questions/11100677/file-to-inputstream

 InputStream is;

    try {
        is = new FileInputStream("c://filename");

        is.close(); 
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    return is;

FileInputStream is an inputStream.

FileInputStream fis = new FileInputStream("c://filename");
InputStream is = fis;
fis.close();  
return is;

Of course, this will not do what you want it to do; the stream you return has already been closed. Just return the FileInputStream and be done with it. The calling code should close it.

-------------------------------------------------------------------------------------------------------------------------------

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.util.Collection;
import java.util.Hashtable;
import java.util.Properties;


import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;


import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

DocumentBuilderFactory df = javax.xml.parsers.DocumentBuilderFactory.newInstance();
DocumentBuilder db = df.newDocumentBuilder();
// File file = new File(css_template_file);
// InputStream in = new InputStream(new FileOutputStream(file));//In

FileInputStream fis = new FileInputStream(css_template_file);
InputStream in = fis;
fis.close();
Document dom = db.parse(new InputSource(in));

改进完成，mark 一下。