RpcInvocation-dubbo源碼解析

public class RpcInvocation implements Invocation, Serializable {

//invoation就是對調用的方法參數的一個封裝，包括方法名，方法參數清單的類類型，方法參數

清單。這個對象說白了就是用Method對象，方法參數清單構造。注意反射中，通過Method對象可以擷取這個方法的參數清單的類類型清單。

    private static final long serialVersionUID = -4355285085441097045L;

    private String methodName;//方法名

    private Class<?>[] parameterTypes;//參數類型類類型清單

    private Object[] arguments;//參數清單

    private Map<String, String> attachments;

    private transient Invoker<?> invoker;

 public RpcInvocation() {

    }

    public RpcInvocation(Invocation invocation, Invoker<?> invoker) {

        this(invocation.getMethodName(), invocation.getParameterTypes(),

                invocation.getArguments(), new HashMap<String, String>(invocation.getAttachments()),

                invocation.getInvoker());

        if (invoker != null) {

            URL url = invoker.getUrl();

            setAttachment(Constants.PATH_KEY, url.getPath());

            if (url.hasParameter(Constants.INTERFACE_KEY)) {

                setAttachment(Constants.INTERFACE_KEY, url.getParameter(Constants.INTERFACE_KEY));

            }

            if (url.hasParameter(Constants.GROUP_KEY)) {

                setAttachment(Constants.GROUP_KEY, url.getParameter(Constants.GROUP_KEY));

            }

            if (url.hasParameter(Constants.VERSION_KEY)) {

                setAttachment(Constants.VERSION_KEY, url.getParameter(Constants.VERSION_KEY, "0.0.0"));

            }

            if (url.hasParameter(Constants.TIMEOUT_KEY)) {

                setAttachment(Constants.TIMEOUT_KEY, url.getParameter(Constants.TIMEOUT_KEY));

            }

            if (url.hasParameter(Constants.TOKEN_KEY)) {

                setAttachment(Constants.TOKEN_KEY, url.getParameter(Constants.TOKEN_KEY));

            }

            if (url.hasParameter(Constants.APPLICATION_KEY)) {

                setAttachment(Constants.APPLICATION_KEY, url.getParameter(Constants.APPLICATION_KEY));

            }

        }

    }

    public RpcInvocation(Invocation invocation) {

        this(invocation.getMethodName(), invocation.getParameterTypes(),

                invocation.getArguments(), invocation.getAttachments(), invocation.getInvoker());

    }

    public RpcInvocation(Method method, Object[] arguments) {//構造方法傳入反射的參數，方法對象

        this(method.getName(), method.getParameterTypes(), arguments, null, null);

    }

    public RpcInvocation(Method method, Object[] arguments, Map<String, String> attachment) {

        this(method.getName(), method.getParameterTypes(), arguments, attachment, null);

    }

    public RpcInvocation(String methodName, Class<?>[] parameterTypes, Object[] arguments) {

        this(methodName, parameterTypes, arguments, null, null);

    }

    public RpcInvocation(String methodName, Class<?>[] parameterTypes, Object[] arguments, Map<String, String> attachments) {

        this(methodName, parameterTypes, arguments, attachments, null);

    }

    public RpcInvocation(String methodName, Class<?>[] parameterTypes, Object[] arguments, Map<String, String> attachments, Invoker<?> invoker) {

        this.methodName = methodName;

        this.parameterTypes = parameterTypes == null ? new Class<?>[0] : parameterTypes;

        this.arguments = arguments == null ? new Object[0] : arguments;

        this.attachments = attachments == null ? new HashMap<String, String>() : attachments;

        this.invoker = invoker;

    }

    @Override

    public Invoker<?> getInvoker() {

        return invoker;

    }

    public void setInvoker(Invoker<?> invoker) {

        this.invoker = invoker;

    }

    @Override

    public String getMethodName() {

        return methodName;

    }

    public void setMethodName(String methodName) {

        this.methodName = methodName;

    }

    @Override

    public Class<?>[] getParameterTypes() {

        return parameterTypes;

    }

    public void setParameterTypes(Class<?>[] parameterTypes) {

        this.parameterTypes = parameterTypes == null ? new Class<?>[0] : parameterTypes;

    }

    @Override

    public Object[] getArguments() {

        return arguments;

    }

    public void setArguments(Object[] arguments) {

        this.arguments = arguments == null ? new Object[0] : arguments;

    }

    @Override

    public Map<String, String> getAttachments() {

        return attachments;

    }

    public void setAttachments(Map<String, String> attachments) {

        this.attachments = attachments == null ? new HashMap<String, String>() : attachments;

    }

    public void setAttachment(String key, String value) {

        if (attachments == null) {

            attachments = new HashMap<String, String>();

        }

        attachments.put(key, value);

    }

    public void setAttachmentIfAbsent(String key, String value) {

        if (attachments == null) {

            attachments = new HashMap<String, String>();

        }

        if (!attachments.containsKey(key)) {

            attachments.put(key, value);

        }

    }

    public void addAttachments(Map<String, String> attachments) {

        if (attachments == null) {

            return;

        }

        if (this.attachments == null) {

            this.attachments = new HashMap<String, String>();

        }

        this.attachments.putAll(attachments);

    }

    public void addAttachmentsIfAbsent(Map<String, String> attachments) {

        if (attachments == null) {

            return;

        }

        for (Map.Entry<String, String> entry : attachments.entrySet()) {

            setAttachmentIfAbsent(entry.getKey(), entry.getValue());

        }

    }

    @Override

    public String getAttachment(String key) {

        if (attachments == null) {

            return null;

        }

        return attachments.get(key);

    }

    @Override

    public String getAttachment(String key, String defaultValue) {

        if (attachments == null) {

            return defaultValue;

        }

        String value = attachments.get(key);

        if (value == null || value.length() == 0) {

            return defaultValue;

        }

        return value;

    }

    @Override

    public String toString() {

        return "RpcInvocation [methodName=" + methodName + ", parameterTypes="

                + Arrays.toString(parameterTypes) + ", arguments=" + Arrays.toString(arguments)

                + ", attachments=" + attachments + "]";

    }