请看下面这个例子 public static String escapeHtmlTags( String input ) { // Check if the string is null or zero length -- if so, return what was sent in. if( input == null input.length() == 0 ) { return input; } // Use a StringBuffer in lieu of String concatenation -- it is mUCh more efficient this way. StringBuffer buf = new StringBuffer(); char ch = ' '; for( int i=0; i<input.length(); i++ ) { ch = input.charAt(i); if( ch == '<' ) { buf.append( "<" ); } else if( ch == '>' ) { buf.append( ">" ); } else { buf.append( ch ); } } return buf.toString(); }