下面的方法可以将一个文件中的所有内容写入一个字符串中
public String file2String() throws TransformerException, IOException {
BufferedReader br = new BufferedReader(new FileReader(
"C://4test//test.xml"));
Writer writer = new StringWriter();
String str = "";
while ((str = br.readLine()) != null) {
writer.write(str + "\n");
writer.flush();
}
String reValue = writer.toString();
System.out.println(reValue);
return reValue;
}