Java读取整个文本文件内容

private String getFileDataStr( String filePath )
{
    File file = new File( filePath );
    if( !file.exists() )
    {
        log.error( "文件不存在！filePath=" + filePath );
        return null;
    }

    try
    {
        FileReader fileReader = new FileReader(file);
        BufferedReader reader = new BufferedReader(fileReader);
        StringBuilder stringBuilder = new StringBuilder();
        String line;
        while(( line = reader.readLine() ) != null )
        {
            stringBuilder.append( line ).append( '\n' );
        }
        reader.close();
        return  stringBuilder.toString();
    }
    catch( Exception e )
    {
        e.printStackTrace();
        return null;
    }
}