config包之ActionConfig浅析

ActionConfig浅析

struts-config.xml文件中每一个<action>元素对应着一个org.apache.struts.action.ActionMapping。ActionMapping继承自org.apache.struts.config.ActionConfig
<action-mappings>元素包含零个或多个<action>元素，<action>元素描述了从特定的请求路径到响应的Action类的影射，<action>元素中包含多个<exception>和<forward>子元素，它们分别配置局部的异常处理及请求转发仅当前的Action所访问。

<action>元素中的className是和<action>元素对应的配置元素。默认为org.apache.struts.action.ActionMapping。
<action>元素中的attribute是设置和Action关联的ActionForm Bean在request或session范围内的属性Key。如：Form Bean存在于request范围内，并且此项设为"myBean"，那么request.getAttribute("myBean")就可以返回该Bean的实例。此项为可选，它在ActionConfig中对应的属性为String attribute。
<action>元素中的forward是指定转发的URL路径。它在ActionConfig中对应的属性为HashMap forward。
<action>元素中的include是指定包含的URL路径。它在ActionConfig中对应的属性为String include。
<action>元素中的input是指定包含输入表单的URL路径。当表单验证失败时，将把请求转发到该URL。它在ActionConfig中对应的属性为String input。
<action>元素中的name是指定和该Action关联的ActionForm Bean的名字。该名字必须在<form-bean>元素中定义过。此项是可选的。它在ActionConfig中对应的属性为String name。
<action>元素中的path是指定访问Action的路径，它以"/"开头，没有扩展名。它在ActionConfig中对应的属性为String path。
<action>元素中的parameter是指定Action的配置参数。在Action类的execute()方法中，可以调用ActionMapping对象的getParocessor()方法来读取该配置参数。它在ActionConfig中对应的属性为String parameter。
<action>元素中的roles是指定允许调用该Action的安全角色。多个角色之间以逗号隔开。在处理请求时，RequestProcessor会根据该配置项来决定用户是否有调用Action的权限。它在ActionConfig中对应的属性为String roles。
<action>元素中的scope是指定ActionForm Bean的存在范围，可选值为request和session。默认为session。它在ActionConfig中对应的属性为String scope。
<action>元素中的type是指定Action类的完整类名。它在ActionConfig中对应的属性为String type。
<action>元素中的unknown项为true，表示可以处理用户发出的所有无效的Action URL。默认为false。它在ActionConfig中对应的属性为boolean unknown。
<action>元素中的validate是指定是否要先调用ActionForm Bean的validate()方法。默认为true。它在ActionConfig中对应的属性为boolean validate。

ActionConfig类中的HashMap exceptions属性对应的是<action></action>包含的零个到多个<exception>元素的信息

ActionConfig类中方法解析
public class ActionConfig implements Serializable {

    protected boolean configured = false;

    protected HashMap exceptions = new HashMap();

    protected HashMap forwards = new HashMap();

    protected ModuleConfig moduleConfig = null;

    public ModuleConfig getModuleConfig() {
        return (this.moduleConfig);
    }

    public void setModuleConfig(ModuleConfig moduleConfig) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }

        this.moduleConfig = moduleConfig;
    }

    protected String attribute = null;

    public String getAttribute() {
        if (this.attribute == null) {
            return (this.name);
        } else {
            return (this.attribute);
        }
    }

    public void setAttribute(String attribute) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.attribute = attribute;
    }

    protected String forward = null;

    public String getForward() {
        return (this.forward);
    }

    public void setForward(String forward) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.forward = forward;
    }

    protected String include = null;

    public String getInclude() {
        return (this.include);
    }

    public void setInclude(String include) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.include = include;
    }

    protected String input = null;

    public String getInput() {
        return (this.input);
    }

    public void setInput(String input) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.input = input;
    }

    protected String multipartClass = null;

    public String getMultipartClass() {
        return (this.multipartClass);
    }

    public void setMultipartClass(String multipartClass) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.multipartClass = multipartClass;
    }

    protected String name = null;

    public String getName() {
        return (this.name);
    }

    public void setName(String name) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.name = name;
    }

    protected String parameter = null;

    public String getParameter() {
        return (this.parameter);
    }

    public void setParameter(String parameter) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.parameter = parameter;
    }

    protected String path = null;

    public String getPath() {
        return (this.path);
    }

    public void setPath(String path) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.path = path;
    }

    //与用户请求的参数相匹配的前缀
    protected String prefix = null;

    public String getPrefix() {
        return (this.prefix);
    }

    public void setPrefix(String prefix) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.prefix = prefix;
    }

    protected String roles = null;

    public String getRoles() {
        return (this.roles);
    }

    public void setRoles(String roles) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.roles = roles;
        if (roles == null) {
            roleNames = new String[0];
            return;
        }
        ArrayList list = new ArrayList();
        while (true) {
            int comma = roles.indexOf(',');
            if (comma < 0)
                break;
            list.add(roles.substring(0, comma).trim());
            roles = roles.substring(comma + 1);
        }
        roles = roles.trim();
        if (roles.length() > 0)
            list.add(roles);
        roleNames = (String[]) list.toArray(new String[list.size()]);
    }

    protected String[] roleNames = new String[0];

    public String[] getRoleNames() {
        return (this.roleNames);
    }

    protected String scope = "session";

    public String getScope() {
        return (this.scope);
    }

    public void setScope(String scope) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.scope = scope;
    }

    ////与用户请求的参数相匹配的后缀
    protected String suffix = null;

    public String getSuffix() {
        return (this.suffix);
    }

    public void setSuffix(String suffix) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.suffix = suffix;
    }

    protected String type = null;

    public String getType() {
        return (this.type);
    }

    public void setType(String type) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.type = type;
    }


    protected boolean unknown = false;

    public boolean getUnknown() {
        return (this.unknown);
    }

    public void setUnknown(boolean unknown) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.unknown = unknown;
    }

    protected boolean validate = true;

    public boolean getValidate() {
        return (this.validate);
    }

    public void setValidate(boolean validate) {
        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        this.validate = validate;
    }

    //将<action></action>包含的<exception>元素的信息保存到HahsMap exceptions
    public void addExceptionConfig(ExceptionConfig config) {

        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        exceptions.put(config.getType(), config);

    }

    //将<action>元素下的forward信息全部保存到HashMap forwards中
    public void addForwardConfig(ForwardConfig config) {

        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        forwards.put(config.getName(), config);

    }

    //根据传入的key从excepions中检索一个ExceptionConfig对象
    public ExceptionConfig findExceptionConfig(String type) {

        return ((ExceptionConfig) exceptions.get(type));

    }

    //把exceptions中所有的Exceptionconfig对象全部取出放入一个ExceptionConfig数组中，并返回该数组
    public ExceptionConfig[] findExceptionConfigs() {

        ExceptionConfig results[] = new ExceptionConfig[exceptions.size()];
        return ((ExceptionConfig[]) exceptions.values().toArray(results));//

    }

    //检索ExceptionConfig对象
    public ExceptionConfig findException(Class type) {

        ExceptionConfig config = null;
        while (true) {

            //在本地检索ExceptionConfig对象
            String name = type.getName();//得到该对象对应实体类的名称
            config = findExceptionConfig(name);
            if (config != null) {
                return (config);
            }

            //在全局中检索ExceptionConfig对象
            config = getModuleConfig().findExceptionConfig(name);
            if (config != null) {
                return (config);
            }

            type = type.getSuperclass();//得到该对象对应实体类的父类的名称，再循环检索
            if (type == null) {
                break;
            }

        }
        return (null); // No handler has been configured

    }

    //根据<forward>元素中的name属性检索Forwardconfig对象
    public ForwardConfig findForwardConfig(String name) {

        return ((ForwardConfig) forwards.get(name));

    }

    //将HashMap forwards中的所有ForwardConfig对象全部保存到一个ForwardConfig数组中，并返回该ForwardConfig数组
    public ForwardConfig[] findForwardConfigs() {

        ForwardConfig results[] = new ForwardConfig[forwards.size()];
        return ((ForwardConfig[]) forwards.values().toArray(results));

    }

    public void freeze() {

        configured = true;

        ExceptionConfig[] econfigs = findExceptionConfigs();
        for (int i = 0; i < econfigs.length; i++) {
            econfigs[i].freeze();
        }

        ForwardConfig[] fconfigs = findForwardConfigs();
        for (int i = 0; i < fconfigs.length; i++) {
            fconfigs[i].freeze();
        }

    }

    //从exceptions中删除一个异常类的名字
    public void removeExceptionConfig(ExceptionConfig config) {

        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        exceptions.remove(config.getType());//config.getType()异常类的名字

    }


    /**
     * Remove the specified forward configuration instance.
     *
     * @param config ForwardConfig instance to be removed
     *
     * @exception IllegalStateException if this module configuration
     *  has been frozen
     */
    public void removeForwardConfig(ForwardConfig config) {

        if (configured) {
            throw new IllegalStateException("Configuration is frozen");
        }
        forwards.remove(config.getName());

    }

    public String toString() {

        StringBuffer sb = new StringBuffer("ActionConfig[");
        sb.append("path=");
        sb.append(path);
        if (attribute != null) {
            sb.append(",attribute=");
            sb.append(attribute);
        }
        if (forward != null) {
            sb.append(",forward=");
            sb.append(forward);
        }
        if (include != null) {
            sb.append(",include=");
            sb.append(include);
        }
        if (input != null) {
            sb.append(",input=");
            sb.append(input);
        }
        if (multipartClass != null) {
            sb.append(",multipartClass=");
            sb.append(multipartClass);
        }
        if (name != null) {
            sb.append(",name=");
            sb.append(name);
        }
        if (parameter != null) {
            sb.append(",parameter=");
            sb.append(parameter);
        }
        if (prefix != null) {
            sb.append(",prefix=");
            sb.append(prefix);
        }
        if (roles != null) {
            sb.append(",roles=");
            sb.append(roles);
        }
        if (scope != null) {
            sb.append(",scope=");
            sb.append(scope);
        }
        if (suffix != null) {
            sb.append(",suffix=");
            sb.append(suffix);
        }
        if (type != null) {
            sb.append(",type=");
            sb.append(type);
        }
        return (sb.toString());

    }
}

原文 http://blog.csdn.net/jason_z/article/details/1798059