如何将参数从 xhtml 传递到支持Bean方法

命令按钮导致此异常：HTTP Status 500 -/encryption.xhtml @17,110 action="#{encryptBean.encrypt(#{encryptBean.path}(}" 无法解析表达式 [#{encryptBean.encrypt(#{encryptBean.path}(}]

    <?xml version="1.0" encoding="ISO-8859-1" ?>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml" 
          xmlns:c="http://java.sun.com/jsf/core"
          xmlns:ui = "http://java.sun.com/jsf/facelets"
          xmlns:h = "http://java.sun.com/jsf/html">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
    <title>encryption</title>
    </head>
    <h:body>
        <h:form>
            <h3>Please enter file path:</h3>
            <label>Path:</label>
            <h:inputText value="#{encryptBean.path}" />
            <h:commandButton value="Encrypt" type="submit" action="#{encryptBean.encrypt(#{encryptBean.path})}"/>
        </h:form>
    </h:body>
    </html>

package bean;
import java.io.IOException;
import java.io.PrintWriter;
import javax.faces.bean.ManagedBean;
import encryptor1.EncryptDecrypt;

@ManagedBean
public class EncryptBean 
{
    private String path="zzz";
    public String getPath() {
        return path;
    }
    public void setPath(String path) {
        this.path = path;
    }
    public static void encrypt(String path) throws IOException, Exception
    {
        //String path= "C:\Users\User\Desktop\secret.txt";
        String encrypted= EncryptDecrypt.encrypt(EncryptDecrypt.readFileAsString(path),path);
        try
        {
            PrintWriter writer = new PrintWriter(EncryptDecrypt.setFilePath(path,"_encrypted"), "UTF-8");
            writer.println(encrypted);
            writer.close();
        } catch (IOException e) {}          
    }

}

当您在受管 Bean 中读取/写入 path 字段时，您可能只制作没有参数的操作按钮方法，如下所示：

<h:commandButton ... action="#{encryptBean.encrypt()}"/>

因此，在方法的签名中：

 public static void encrypt(/* Nothing here */) throws IOException, Exception {

顺便说一下，您应该使该方法非静态以启用字段path的使用，或者将它们都static。首选使用第一种方法。

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