abstractdomainobject.java

利用java反射机制

package org.julp;

import java.beans.*;
import java.util.*;
import java.lang.reflect.*;

    /**
     * Normally to make your object able to persist you need to extend this object
     * If you can't or don't want to extend, just make your class
     * implement org.julp.DomainObject interface and copy and paste members
     * and methods from org.julp.AbstractDomainObject into your class.
     */

public abstract class AbstractDomainObject implements DomainObject, java.io.Serializable, Cloneable {
    
    protected DataHolder originalValues = null;
    protected int objectId = 0;
    protected char sqlStatus = '\u0000';
    protected boolean loaded = false;
    protected boolean loading = false;
    protected boolean modified = false;
    public String TEMP = null;  //NetBeans bug workaround: debugger does not display value of char datatype
  
    
    public String toString() {
        StringBuffer sb = new StringBuffer();
        Object value = null;
        Method[] methods = getClass().getMethods();
        for (int i = 0;i < methods.length;i++){
            String methodName = methods[i].getName();
            if (methodName.equals("getValuesAsHtml") || methodName.equals("getClass")){
                continue;
            }
            if (methodName.startsWith("get") && methods[i].getParameterTypes().length == 0){
                try{
                    value = methods[i].invoke(this, new Object[0]);
                }catch (IllegalAccessException eae){
                    continue;                    
                }catch (InvocationTargetException ite){                    
                    continue;
                }
                String s = methodName.substring(3, 4).toLowerCase();
                StringBuffer fieldName = new StringBuffer(s);
                fieldName.append(methodName.substring(4));
                sb.append(fieldName);
                sb.append("=");
                if (value == null){
                    sb.append("");
                }else{
                    sb.append(value);
                }
                sb.append("&");
            }
        }
        sb.deleteCharAt(sb.length() - 1);
        return sb.toString();
    }
    
    public void setOriginalValues(DataHolder originalValues) {
        this.originalValues = originalValues;
    }
    
    public DataHolder getOriginalValues() {
        return this.originalValues;
    }
    
    public void setOriginalValue(String fieldName, Object value) {
        if (originalValues == null) {
            throw new IllegalArgumentException("setOriginalValue: DataHolder not set");
        }
        originalValues.setObject(fieldName, value);
    }
    
    public Object getOriginalValue(String fieldName) {
        if (originalValues == null) {
            return null;
        }
        return this.originalValues.getObject(fieldName);
    }
    
    public char getSqlStatus() {
        return this.sqlStatus;
    }
    
    /**
     * This method set sqlStatus
     *
     */    
    public void setSqlStatus(char sqlStatus) {
        this.sqlStatus = sqlStatus;
        TEMP = new String(String.valueOf(sqlStatus));
    }
    
    /** Getter for property objectId.
     * @return Value of property objectId.
     *
     */
    public int getObjectId() {
        return objectId;
    }
    
    /**     
     *  Every time  DomainObjectFactory is loaded this object it assigned objectId
     */

    public void setObjectId(int objectId) {
        this.objectId = objectId;
    }
    
    public boolean store() {
        if (originalValues != null && originalValues.getFieldCount() > 0){
            setSqlStatus(UPDATED);
            return true;
        }
        return false;
    }
    
    public boolean remove() {
        if (originalValues != null && originalValues.getFieldCount() > 0){
            setSqlStatus(DELETED);
            return true;
        }
        return false;
    }
    
    public boolean create() {
        if (originalValues == null || originalValues.getFieldCount() < 1){
            setSqlStatus(INSERTED);
            return true;
        }
        return false;
    }    
    
    public boolean load() {
        setLoading(true);
        if (originalValues != null && originalValues.getFieldCount() > 0){          
            try{
                List param = new ArrayList(1);
                for(int fieldIndex = 1; fieldIndex <= originalValues.getFieldCount(); fieldIndex++){
                    param.clear();
                    String fieldName = originalValues.getFieldName(fieldIndex);
                    Object value = originalValues.getObject(fieldIndex);
                    PropertyDescriptor pd = new PropertyDescriptor(fieldName, this.getClass());
                    Method writeMethod = pd.getWriteMethod();                    
                    param.add(value);
                    writeMethod.invoke(this, param.toArray());
                }
            }catch(IntrospectionException ie){
                throw new RuntimeException(ie);
            }catch(IllegalAccessException iae){
                throw new RuntimeException(iae);
            }catch(InvocationTargetException ite){
                throw new RuntimeException(ite);
            }
            setLoading(false);
            setLoaded(true);
            return true;
        }
        setLoading(false);
        return false;
    }
    
    /** Getter for property loaded.
     * @return Value of property loaded.
     *
     */
    public boolean isLoaded() {
        return loaded;
    }
    
    /** Setter for property loaded.
     * @param loaded New value of property loaded.
     *
     */
    public void setLoaded(boolean loaded) {
        this.setSqlStatus(ORIGINAL);
        this.loaded = loaded;
    }
    
    /**
     *  This is convinient method to use with JSP.
     *  Make sure not to call this method from another method
     *  of this object (or subclass) started with "get",
     *  or you will get endless loop
     */
    
    public java.lang.String getValuesAsHtml() {
        StringBuffer sb = new StringBuffer();
        Object value = null;
        Object[] arg = new Object[0];
        Method[] methods = getClass().getMethods();
        for (int i = 0;i < methods.length;i++){
            String methodName = methods[i].getName();
            if (methodName.equals("getValuesAsHtml") || methodName.equals("getClass")){
                continue;
            }
            if (methodName.startsWith("get") && methods[i].getParameterTypes().length == 0){
                try{
                    value = methods[i].invoke(this, arg);
                }catch (IllegalAccessException eae){
                    continue;
                }catch (InvocationTargetException ite){
                    continue;
                }
                String s = methodName.substring(3, 4).toLowerCase();
                StringBuffer fieldName = new StringBuffer(s);
                fieldName.append(methodName.substring(4));
                sb.append(fieldName);
                sb.append("=");
                if (value == null){
                    sb.append("");
                }else{
                    try{
                        sb.append(java.net.URLEncoder.encode(value.toString(), "UTF-8"));
                    }catch (java.io.UnsupportedEncodingException uee){
                        throw new RuntimeException(uee);
                    }
                }
                sb.append("&");
            }
        }
        sb.deleteCharAt(sb.length() - 1);
        return sb.toString();
    }
    
    /**
     * Indicator that this object in proccess of loading with values from database     
     */
    
    public boolean isLoading() {
        return this.loading;
    }
    
    public void setLoading(boolean loading) {
        this.loading = loading;
    }

    /**
     * Indicator that this object is modified. You have to call it yourself
     *
     */    
    public boolean isModified() {
        return this.modified;
    }
    
    public void setModified(boolean modified) {
        this.modified = modified;
    }
}