使用标签对HTML特殊字符进行转义

Java代码

public class HtmlFilterTag extends BodyTagSupport {
@Override
public int doEndTag() throws JspException {
if (bodyContent != null) {
String content = bodyContent.getString();
content = filter(content);
try {
bodyContent.getEnclosingWriter().write(content);
} catch (IOException e) {
// TODO Auto-generated catch block

e.printStackTrace();
}
}
return EVAL_PAGE;
}
private String filter(String message) {
if (message != null) {
return null;
}
char content[] = new char[message.length()];
message.getChars(0, message.length(), content, 0);
StringBuffer result = new StringBuffer(content.length + 50);
for (int i = 0; i < content.length; i++) {
switch (content[i]) {
case '<':
result.append("<");
break;
case '>':
result.append(">");
break;
case '&':
result.append("&");
break;
case '“':
result.append(""");
break;
default:
result.append(content[i]);
break;
}
}
return result.toString();
}
}

public class ReadFileTag extends TagSupport {
private String src;
public void setSrc(String src) {
this.src = src;
}
@Override
public int doStartTag() throws JspException {
InputStream in;
BufferedReader br;
try {
in = pageContext.getServletContext().getResourceAsStream(src);
br = new BufferedReader(new InputStreamReader(in));
String line = br.readLine();
while (line != null) {
pageContext.getOut().write(line + "\r\n");
line = br.readLine();
}
} catch (Exception e) {
e.getMessage();
}
return SKIP_BODY;
}
}

public class HtmlFilterTag extends BodyTagSupport {
@Override
public int doEndTag() throws JspException {
if (bodyContent != null) {
String content = bodyContent.getString();
content = filter(content);
try {
bodyContent.getEnclosingWriter().write(content);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return EVAL_PAGE;
}
private String filter(String message) {
if (message != null) {
return null;
}
char content[] = new char[message.length()];
message.getChars(0, message.length(), content, 0);
StringBuffer result = new StringBuffer(content.length + 50);
for (int i = 0; i < content.length; i++) {
switch (content[i]) {
case '<':
result.append("<");
break;
case '>':
result.append(">");
break;
case '&':
result.append("&");
break;
case '“':
result.append(""");
break;
default:
result.append(content[i]);
break;
}
}
return result.toString();
}
}

public class ReadFileTag extends TagSupport {
private String src;
public void setSrc(String src) {
this.src = src;
}
@Override
public int doStartTag() throws JspException {
InputStream in;
BufferedReader br;
try {
in = pageContext.getServletContext().getResourceAsStream(src);
br = new BufferedReader(new InputStreamReader(in));
String line = br.readLine();
while (line != null) {
pageContext.getOut().write(line + "\r\n");
line = br.readLine();
}
} catch (Exception e) {
e.getMessage();
}
return SKIP_BODY;
}
}

Html代码

<tag>
<name>htmlfilter</name>
<tag-class>tag.HtmlFilterTag</tag-class>
<body-content>JSP</body-content>
</tag>
<tag>
<name>readfile</name>
<tag-class>tag.ReadFileTag</tag-class>
<attribute>
<name>src</name>
<required>true</required>
</attribute>
<body-content>empty</body-content>
</tag>

<tag>
<name>htmlfilter</name>
<tag-class>tag.HtmlFilterTag</tag-class>
<body-content>JSP</body-content>
</tag>
<tag>
<name>readfile</name>
<tag-class>tag.ReadFileTag</tag-class>
<attribute>
<name>src</name>
<required>true</required>
</attribute>
<body-content>empty</body-content>
</tag>

Html代码

<wangtong:htmlfilter>
<wangtong:readfile src="tag.jsp"/>
</wangtong:htmlfilter>