用Java编写控制台输出到文件

Question

所以我想知道是否有可能将所有控制台输出写入Java之外的单独文件？我知道Printwriter和Filewriter方法.但是,根据我的经验,如果我在一个方法中使用它们,那些将会起作用,但我认为我不能用我现在的代码那样做.以下是我所拥有的......

Java代码

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

public class XMLTagParser extends DefaultHandler 
{
    private int i;

    public XMLTagParser()
    {
        traverse(new File("C:/Documents and Settings/user/workspace/Intern Project/Proposals/Converted Proposals/Extracted Items"));
    }

    private static final class SaxHandler extends DefaultHandler 
    {

        private StringBuffer buffer;
        private String heading;
        private boolean inHeading;

        public void startElement(String uri, String localName, String qName, Attributes attrs)
        {
            if ("w:pStyle".equals(qName))
            {
                String val = attrs.getValue("w:val");

                if (val.contains("Heading"))
                {
                    if (isHeading(val))
                    {
                        System.out.println(val);
                        inHeading = true;
                    }
                }
            }

            if("w:t".equals(qName))
            {
                if (inHeading == true)
                {
                    buffer = new StringBuffer();
                }
            } 
        }

        public void characters(char buff[], int offset, int length) throws SAXException
        {
            String s = new String(buff, offset, length);

            if(buffer != null)
            {
                buffer.append(s);
                heading = heading += s;
            }   
        }

        public void endElement(String uri, String localName, String qName)
        {
            buffer = null; 

            //if the qName is "w:p" and it is in the heading, print out the heading and then reset
            if ("w:p".equals(qName) && inHeading == true)
            {       
                System.out.println(heading);        

                heading = "";
                inHeading = false;      
            }   
        }

        // method to verify whether element is an actual heading
        private static boolean isHeading(String heading)
        {
            String headingNumber = heading.substring(7,8);
            String headingName = heading.substring(0,7);

            if (headingName.equals("Heading"))
            {
                if (headingNumber.equals("1") 
                        || headingNumber.equals("2")
                        || headingNumber.equals("3")
                        || headingNumber.equals("4")
                        || headingNumber.equals("5")
                        || headingNumber.equals("6"))
                {
                    return true;
                }
            }

            return false; 
        }
    }

    /*private void writeFile(File file)
    {
        try 
        {
            PrintWriter out = new PrintWriter(new FileWriter(file + "/" + i++));
            out.close();
        } 
        catch (IOException e) 
        {
            e.printStackTrace(System.out);
        }
    }*/

    private void traverse(File directory)
    {
        //Get all files in directory
        File[] files = directory.listFiles();
        for (File file : files)
        {
            if (file.getName().equals("document.xml"))
            {
                try 
                {
                    // creates and returns new instance of SAX-implementation:
                    SAXParserFactory factory = SAXParserFactory.newInstance();

                    // create SAX-parser...
                    SAXParser parser = factory.newSAXParser();

                    // prints out the current working proposal, traversing up the directory structure
                    System.out.println(file.getParentFile().getParentFile().getName());

                    // .. define our handler:
                    SaxHandler handler = new SaxHandler();

                    // and parse:
                    parser.parse(file.getAbsolutePath(), handler);

                    try 
                    {
                        // instantiates new printwriter which writes out to a file
                        PrintWriter out = new PrintWriter(new FileWriter(file.getParentFile().getParentFile() + "/" + i++ + ".txt"));
                        out.close();
                    } 
                    catch (IOException e) 
                    {
                        e.printStackTrace(System.out);
                    }
                } 
                catch (Exception ex) 
                {
                    ex.printStackTrace(System.out);
                }
            }
            else if (file.isDirectory())
            {
                //It's a directory so (recursively) traverse it
                traverse(file);
            }
        }
    }
}

所以我已经在那里实例化了printwriter,但显然如果我没有什么可写的那就没有用.所以我不确定如何打印出要写入该文件的控制台.有任何想法吗？提前致谢.

Answer 1

如果您开始使用自己的文件记录器,您将花费更多时间处理io问题,滚动文件,文件大小等.你应该使用log4j代替! 它将处理这样的事情并使您的日志记录更加灵活.它几乎是java日志记录的标准.

Answer 2

如果你真的想要,你可以重定向System.out到这样的任何PrintStream一个:

PrintStream stream = new PrintStream("filename.txt");
System.setOut(stream);