How to deal with garbled characters in Servlet in Java

Author：Eve Cole Update Time：2024-11-19 08:48:02

When deploying a webservices program today, the servlet that obtains data from the page encountered a garbled problem. In the servlet, I added the text request.setCharacterEncoding("GB2312"); to the code, but the garbled problem still occurred.
Find information online, as follows: JAVA is Unicode encoding, you first convert it to ISO8859-1, and then convert it to GBK or GB2312.

java code

Copy the code code as follows:

request.setCharacterEncoding("ISO8859-1");
ad=request.getParameter("name");
byte[] temp3 = ad.getBytes("GBK");
String str = new String(temp3);

This is Chinese!
There is an easier way, which is to set the encoding conversion directly in the server. TOMCAT5.0.28 is used.
Find the SERVER.XML file in the ../Tomcat 5.0/conf directory, open it with WordPad, and set it as follows:
Just add an attribute inside, URIEncoding="GBK"
The test is passed and it is done. Then there is what role the sentence request.setCharacterEncoding("GB2312") plays. If it cannot solve the messy problem, what role do we use it to play? The information is organized as follows:
(1) The JSP page is in Chinese, but when you look at it, it is garbled:
The solution is to encode the JSP page. Because of the encoding problem when JSP is converted into a Java file, some servers use ISO-8859-1 by default. If Chinese is directly entered into a JSP, JSP treats it as ISO8859. -1 is definitely a problem. We can confirm this by looking at the Java intermediate file generated by Jasper.

(2) When using the Request object to obtain the Chinese character code submitted by the customer, garbled characters will appear:
The solution is to configure a filter, which is a Servelet filter. The code is as follows:

Copy the code code as follows:

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {

request.setCharacterEncoding("GBK");

// Pass control to the next filter
chain.doFilter(request, response);
}

Configure web.xml

Copy the code code as follows:

<filter></filter>
<filter-name></filter-name>Set Character Encoding
<filter-class></filter-class>SetCharacterEncodingFilter

<filter-mapping></filter-mapping>
<filter-name></filter-name>Set Character Encoding
<url-pattern></url-pattern>/*

If this situation still occurs in your case, you can go down and see if you have the fourth situation. Whether the data submitted by your Form is submitted using get. Generally speaking, there is no problem if you use post to submit. If so, take a look at the fourth solution.

There is also the processing of information containing Chinese characters. The processing code is:

Copy the code code as follows:

public String toUni(String gbStr){
String uniStr = "";
if(gbStr == null){
gbStr = "";
}
try{
byte[] tempByte = gbStr.getBytes("GB2312");
uniStr = new String(tempByte,"ISO8859_1");
}catch(Exception ex){
}
return uniStr;
}
}

You can also perform direct conversion. First, encode the obtained string with ISO-8859-1, then store the encoding in a byte array, and then convert the array into a string object. For example :
String str=request.getParameter("girl");
Byte B[]=str.getBytes("ISO-8859-1");
Str=new String(B);
Through the above conversion, any information submitted can be displayed correctly.
(3) When the Formget request uses request.getParameter("name") on the server, garbled characters are returned; setting the Filter according to tomcat's method does not work, or using request.setCharacterEncoding("GBK"); does not work either. The problem is that In terms of the method of processing parameter transfer: If you use the doGet(HttpServletRequest request, HttpServletResponse response) method in the servlet to process it, even if it is written before:

Copy the code code as follows:

request.setCharacterEncoding("GBK");
response.setContentType("text/html;charset=GBK");

It doesn't work either, the Chinese returned is still garbled! ! ! If you change this function to doPost(HttpServletRequest request, HttpServletResponse response) everything will be OK.
Similarly, when using two JSP pages to process form input, the reason why Chinese can be displayed is because the post method is used to pass it, and changing it to the get method still does not work.
It can be seen that you need to pay attention when using the doGet() method in servlet or the get method in JSP. After all, this involves passing parameter information through the browser, which is likely to cause conflicts or mismatches in commonly used character sets.
//This place is understood as request.setCharacterEncoding("GBK"); what is set is the body in the request, not the header part. When making a get request, the parameters are placed after the URL, not in the body, so request.setCharacterEncoding is used at this time ("GBK") did not work. If I changed to post submission, there would be no problem. After testing, it passed!!

The solution is:
1) Open the server.xml file of tomcat, find the block, and add the following line:
URIEncoding=”GBK”
The complete should be as follows:

Copy the code code as follows:

2) Restart tomcat, everything is OK.
Explanation given by tomact.org
This specifies the character encoding used to decode the URI bytes, after %xx decoding the URL. If not specified, ISO-8859-1 will be used. In other words, the bytes of the URI are converted, request.setCharacterEncoding("GBK") The request has also been converted, and the problem is ok!

(4) There are Chinese characters on the JSP page and Chinese characters on the buttons, but when viewing the page through the server, garbled characters appear:
The solution is: First, the localized message text should not be included directly in the JSP file, but the text should be obtained from the Resource Bundle through the <bean:message> tag. You should put your Chinese text in the Application.properties file. This file is placed under WEB-INF/classes/*. For example, if I have two labels for name and age on the page, I first need to create an Application.properties. The content inside should be name="name" age="age", then I put this file under WEB-INF/classes/properties/, and then encode it according to the Application.properties file to create a Chinese Resource file, assuming the name is Application_cn.properties. The native2ascii command is provided in the JDK, which can realize character encoding conversion. Find the directory where you placed the Application.properties file in the DOS environment. Execute the command in the DOS environment. The Chinese resource file Application_cn.properties encoded in GBK will be generated: native2ascii ?encoding gbk Application.properties Application_cn.properties. Execute the above command. In the future, the Application_cn.properties file with the following content will be generated: name=u59d3u540d age=u5e74u9f84, configured in Struts-config.xml: <message-resources parameter="properties.Application_cn"></message-resources>. At this point, more than half of it is basically done. Then you have to write on the JSP page. For the label of the name, you need to write <bean:message key=""name"">. This will appear on the page. The Chinese name will appear, the same goes for the age, and the Chinese characters on the button are also processed in the same way.
(5) The code written to the database is garbled:
Solution: Configure a filter, which is a Servelet filter. The code is the same as the second time.
If you are directly connected to the database through JDBC, the configuration code is as follows: jdbc:mysql://localhost:3306/workshopdb? useUnicode=true&characterEncoding=GBK, so as to ensure that the code in the database is not garbled.
If you are linking through the data source, you cannot write it like this. First, you have to write it in the configuration file. The place to configure the data source in tomcat 5.0.19 is under C:Tomcat 5.0confCatalinalocalhost. I created The project is workshop, and the directory where it is placed is under webapp. The configuration file of workshop.xml is as follows:

Copy the code code as follows:

<context debug="0" path="/workshop" docbase="workshop"></context>reloadable="true" >

<resource name="jdbc/WorkshopDB"></resource>auth="Container"
type="javax.sql.DataSource" />

<resourceparams name="jdbc/WorkshopDB"></resourceparams>
<parameter></parameter>
<name></name>factory
<value></value>org.apache.commons.dbcp.BasicDataSourceFactory

<parameter></parameter>
<name></name>maxActive
<value></value>100

<parameter></parameter>
<name></name>maxIdle
<value></value>30

<parameter></parameter>
<name></name>maxWait
<value></value>10000

<parameter></parameter>
<name></name>username
<value></value>root

<parameter></parameter>
<name></name>password
<value></value>

<parameter></parameter>
<name></name>driverClassName
<value></value>com.mysql.jdbc.Driver

Pay special attention to the places in bold. It is different from the direct link to JDBC. If you configure it correctly, when you enter Chinese, it will be Chinese in the database. One thing to note is that when you display The data page also needs this line of code. It should be noted that some front desk staff use Dreamver to write the code. When writing a Form, they change it to a jsp. There is one thing to pay attention to, and that is the submission of Action in Dreamver. The method is request, and you need to send it over, because there are two methods of JSP submission: POST and GET, but the code submitted by these two methods is still very different in terms of encoding. This is Explained later. </bean:message>< /bean:message>