Java-将多行字符串写入文件

Question

I have a string with multilines in it as shown below

<?xml version="1.0" encoding="UTF-8"?>
<books>

    <book publishyear="1990">
        <name>Harry Potter</name>
    </book> 
</books>

how do I write this to a file? I have tried with buffered writer but, it doesn't take the string in multiline.

 try{
           FileWriter fstream = new FileWriter("D:/temp.txt");
           BufferedWriter out = new BufferedWriter(fstream);
           out.write(" <?xml version="1.0" encoding="UTF-8"?>
<books>

    <book publishyear="1990">
        <name>Harry Potter</name>
    </book> 
</books>");

           out.close();
  }catch (Exception e){//Catch exception if any
        System.err.println("Error: " + e.getMessage());
    }

Answer 1

Never ever write XML documents manually. You will fail in file encoding, you will fail in syntax errors. Always use DOM ore something similar. Your demo code already contains errors.

Answer 2

This isn't related to writing a string or BufferedWriter.

Java does not have multiline strings, so you'll have to concatenate strings if you want them on multiline in the source code. You also need to replace actual newlines with the escaped \\n character, and escape " with \\"

That is, you do:

String foo = "<?xml version="1.0" encoding=\"UTF-8\"?>\n"+
"<books>\n"+
"   <book publishyear=\"1990\">\n"+
"        <name>Harry Potter</name>\n"+
"    </book>\n"+
"</books>";

out.write(foo);

You can write all this on one line in your source code too if you want:

out.write("<?xml version="1.0" encoding=\"UTF-8\"?>\n<books>\n ... etc.etc."));

Answer 3

You should escape the quotes and use a PrintWriter, which provides a println method.

PrintWriter out = new PrintWriter(new BufferedWriter(fstream));

out.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
out.println("<books>)";

Alternatively you can append line terminators to your string:

 out.write("<books>\r\n");

Answer 4

You can definitely write on a new line by using BufferedWriter
See below code as an example, incorporate with your own logic (giving example of writing new line in a file write)

BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));
writer.write("I am the first Line");
writer.newLine();
writer.write("I am in the second Line");

writer.close();  

You need to make the use of newLine() method present in BufferedWriter
Hope this helps and you don't have to change your code to new output stream :)