Demo:把文件内容读入一个String

public static String readFileToString() throws IOException {
//		File dirs = new File(".");
StringBuffer fileData = new StringBuffer(1000);//Constructs a string buffer with no characters in it and the specified initial capacity
BufferedReader reader = new BufferedReader(new FileReader("test.txt"));
char[] buf = new char[1024];
int numRead = 0;
while ((numRead = reader.read(buf)) != -1) {
String readData = String.valueOf(buf, 0, numRead);
fileData.append(readData);
buf = new char[1024];
}
reader.close();
String returnStr = fileData.toString();
System.out.println(returnStr);
return returnStr;
}