2025-06-09 22:12:42
.286 31140-31140 getEndpoint com
.example
.kucun2 D getEndpoint: url_add_Dingdan
2025-06-09 22:12:42
.290 31140-31140 System
.err com
.example
.kucun2 W R绫绘湭鎵惧埌: com
.example
.kucun2
.R$String
2025-06-09 22:12:42
.324 31140-31140 getEndpoint com
.example
.kucun2 D endpoint: nullpackage com
.example
.kucun2
.entity
.data;
import android
.util
.Log;
import com
.example
.kucun2
.function
.MyAppFnction;
public abstract class SynchronizableEntity implements EntityClassGrassrootsid {
/**
* 添加url
* @param type 操作增删改查
* @return 返回相对url
*/
public String getEndpoint(String type){
//从String
.xml获取url
Log
.d("getEndpoint", "getEndpoint: "+"url_"+type+"_"+
this.getClass().getSimpleName
());
return MyAppFnction
.getStringResource("String","url_"+type+"_"+
this.getClass().getSimpleName
());
}
}
package com
.example
.kucun2
.entity
.data;
import android
.util
.Log;
import androidx
.annotation
.NonNull;
import com
.google
.gson
.Gson;
import java
.io
.IOException;
import java
.lang
.reflect
.Method;
import java
.lang
.reflect
.ParameterizedType;
import java
.lang
.reflect
.Proxy;
import java
.lang
.reflect
.Type;
import java
.util
.ArrayList;
import java
.util
.Arrays;
import java
.util
.Collection;
import java
.util
.HashMap;
import java
.util
.HashSet;
import java
.util
.Iterator;
import java
.util
.List;
import java
.util
.ListIterator;
import java
.util
.Map;
import java
.util
.Objects;
import java
.util
.Set;
import okhttp3
.Call;
import okhttp3
.Callback;
import okhttp3
.MediaType;
import okhttp3
.OkHttpClient;
import okhttp3
.Request;
import okhttp3
.RequestBody;
import okhttp3
.Response;
/**
支持数据变更自动同步的泛型集合类
@param <T> 继承自 SynchronizableEntity 的实体类型
*/
public class SynchronizedList<T extends EntityClassGrassrootsid> implements List<T> {
private final List<T> list = new ArrayList<>
();
private final OkHttpClient client = new OkHttpClient
();
private static final Gson gson = new Gson
();
private static final MediaType JSON = MediaType
.get(“application/json; charset=utf-8”);
private final Class<T> entityClass; // 类型标记
// 添加批量操作模式标志
private boolean batchMode = false;
// 属性变更监听器
private final List<PropertyChangeListener<T>> listeners = new ArrayList<>
();
// 直接接受Class参数的构造函数
public SynchronizedList(Class<T> entityClass) {
this.entityClass = entityClass;
}
// 安全的类型转换方法
private T safeCast(Object o) {
if (o != null && entityClass
.isInstance(o)) {
return entityClass
.cast(o);
}
return null;
}
public interface PropertyChangeListener<T> {
void onPropertyChange(T entity, String propertyName, Object oldValue, Object newValue);
}
public void addPropertyChangeListener(PropertyChangeListener<T> listener) {
listeners
.add(listener);
}
public void removePropertyChangeListener(PropertyChangeListener<T> listener) {
listeners
.remove(listener);
}
// 添加方法来获取原始对象
@SuppressWarnings(“unchecked”)
public T getOriginal(T proxy) {
if (proxy == null) return null;
// 检查是否为代理对象
if (java
.lang
.reflect
.Proxy
.isProxyClass(proxy
.getClass())) {
try {
java
.lang
.reflect
.InvocationHandler handler =
java
.lang
.reflect
.Proxy
.getInvocationHandler(proxy);
if (handler instanceof IProxyHandler) {
Object original = ((IProxyHandler) handler)
.getOriginal
();
// 安全类型检查
if (entityClass
.isInstance(original)) {
return (T) original;
}
}
} catch (Exception e) {
Log
.e("SynchronizedList", "Failed to get proxy handler", e);
}
}
return proxy;
}
/**
同步实体到后端
@param entity 要同步的实体
*/
private void syncEntity(T entity) {
if (batchMode) return;
String operation = “add”;
T originalEntity = getOriginal(entity);
String endpoint = originalEntity
.getEndpoint(operation);
String json = gson
.toJson(originalEntity);
Log
.d(“getEndpoint”, "endpoint: "+endpoint);
RequestBody body = RequestBody
.create(json, JSON);
Request request = new Request
.Builder
()
.url(endpoint)
.method(getHttpMethod(operation), body)
.build
();
client
.newCall(request)
.enqueue(new Callback
() {
@Override
public void onFailure(@NonNull Call call, @NonNull IOException e) {
Log
.e(“SynchronizedList”, "同步失败: " + entity
.getClass().getSimpleName
(), e);
}
@Override
public void onResponse(@NonNull Call call, @NonNull Response response) {
if (!response
.isSuccessful
()) {
Log
.e("SynchronizedList", "同步失败: " +
response
.code
() + " - " + response
.message
());
}
response
.close
();
}
});
}
// 添加用于批量操作的方法
public void beginBatch
() {
this.batchMode = true;
}
public void endBatch
() {
this.batchMode = false;
// 批量结束后触发一次全量同步
syncAllEntities
();
}
private void syncAllEntities
() {
for (T entity : list) {
syncEntity(entity);
}
}
private String getHttpMethod(String operation) {
switch (operation) {
case “add”:
return “POST”;
case “update”:
return “PUT”;
case “delete”:
return “DELETE”;
default:
return “POST”;
}
}
// 获取类实现的所有接口（包括父类接口）
private Class<?>[] getInterfaces(Class<?> clazz) {
Set<Class<?>> interfaces = new HashSet<>
();
while (clazz != null) {
interfaces
.addAll(Arrays
.asList(clazz
.getInterfaces
()));
clazz = clazz
.getSuperclass
();
}
return interfaces
.toArray(new Class<?>[0]);
}
/**
创建代理对象，用于监听属性变更 */
// 优化 createProxy 方法
private T createProxy(T original) {
if (original == null) return null;
// 获取实体类实现的所有接口
Set<Class<?>> interfaces = new HashSet<>
();
Class<?> clazz = original
.getClass();
// 收集所有接口，包括继承链中的接口
while (clazz != null) {
interfaces
.addAll(Arrays
.asList(clazz
.getInterfaces
()));
clazz = clazz
.getSuperclass
();
}
// 创建代理对象
return (T) Proxy
.newProxyInstance(
original
.getClass().getClassLoader
(),
interfaces
.toArray(new Class<?>[0]),
new EntityProxyHandler(original)
);
// if (!entityClass
.isInstance(original)) {
// throw new IllegalArgumentException(“Invalid entity type”);
// }
// // 这里使用动态代理模式监听setter方法调用
// return (T) java
.lang
.reflect
.Proxy
.newProxyInstance(
// original
.getClass().getClassLoader
(),
// original
.getClass().getInterfaces
(),
// (proxy, method, args) -> {
// // 只拦截setter方法
// if (method
.getName
().startsWith(“set”) && args
.length == 1) {
// String propertyName = method
.getName
().substring(3);
// propertyName = propertyName
.substring(0, 1)
.toLowerCase
() + propertyName
.substring(1);
//
// // 获取旧值
// Object oldValue = original
.getClass()
//
.getMethod(“get” + propertyName
.substring(0, 1)
.toUpperCase
() + propertyName
.substring(1))
//
.invoke(original);
//
// // 调用原始方法
// Object result = method
.invoke(original, args);
//
// // 触发监听器
// for (PropertyChangeListener<T> listener : listeners) {
// listener
.onPropertyChange(original, propertyName, oldValue, args[0]);
// }
//
// // 自动同步到后端
// syncEntity(original);
// return result;
// }
// return method
.invoke(original, args);
// }
// );
}
// 以下是List接口的实现
@Override
public int size
() {
return list
.size
();
}
@Override
public boolean isEmpty
() {
return list
.isEmpty
();
}
@Override
public boolean contains(Object o) {
return list
.contains(o);
}
@NonNull
@Override
public Iterator<T> iterator
() {
return list
.iterator
();
}
@NonNull
@Override
public Object[] toArray
() {
return list
.toArray
();
}
@NonNull
@Override
public <T1> T1[] toArray(@NonNull T1[] a) {
return list
.toArray(a);
}
@Override
public boolean add(T t) {
T proxy = createProxy(t);
boolean result = list
.add(proxy);
if (!batchMode) {
syncEntity(proxy);
}
return result; // 添加时创建代理
}
@Override
public boolean remove(Object o) {
T entity = safeCast(o);
if (entity != null) {
syncEntity((T) entity); // 删除前同步
}
return list
.remove(o);
}
@Override
public boolean containsAll(@NonNull Collection<?> c) {
return list
.containsAll(c);
}
@Override
public boolean addAll(@NonNull Collection<? extends T> c) {
boolean modified = false;
for (T t : c) {
modified |= add(t);
}
return modified;
}
@Override
public boolean addAll(int index, @NonNull Collection<? extends T> c) {
for (T t : c) {
add(index++, t);
}
return true;
}
@Override
public boolean removeAll(@NonNull Collection<?> c) {
for (Object o : c) {
T entity = safeCast(o);
if (entity != null) {
syncEntity(entity);
}
}
return list
.removeAll(c);
}
@Override
public boolean retainAll(@NonNull Collection<?> c) {
List<T> toRemove = new ArrayList<>
();
for (T t : list) {
if (!c
.contains(t)) {
toRemove
.add(t);
}
}
// 使用安全转换
for (T entity : toRemove) {
syncEntity(entity);
}
return list
.retainAll(c);
}
@Override
public void clear
() {
for (T t : list) {
syncEntity(t); // 清空前同步
}
list
.clear
();
}
@Override
public T get(int index) {
return list
.get(index);
}
@Override
public T set(int index, T element) {
T old = list
.set(index, createProxy(element));
if (old != null) {
syncEntity(old); // 替换旧元素前同步
}
return old;
}
@Override
public void add(int index, T element) {
list
.add(index, createProxy(element));
}
@Override
public T remove(int index) {
T removed = list
.remove(index);
if (removed != null) {
syncEntity(removed); // 删除前同步
}
return removed;
}
@Override
public int indexOf(Object o) {
return list
.indexOf(o);
}
@Override
public int lastIndexOf(Object o) {
return list
.lastIndexOf(o);
}
@NonNull
@Override
public ListIterator<T> listIterator
() {
return list
.listIterator
();
}
@NonNull
@Override
public ListIterator<T> listIterator(int index) {
return list
.listIterator(index);
}
@NonNull
@Override
public List<T> subList(int fromIndex, int toIndex) {
return list
.subList(fromIndex, toIndex);
}
// 触发属性变更通知
// 添加类型安全的属性监听
private void firePropertyChange(T entity, String propertyName, Object oldValue, Object newValue) {
if (oldValue != null && newValue != null && oldValue
.equals(newValue)) {
return; // 值未变化时不触发监听
}
for (PropertyChangeListener<T> listener : listeners) {
try {
listener
.onPropertyChange(entity, propertyName, oldValue, newValue);
} catch (Exception e) {
Log
.e("SynchronizedList", "Listener error", e);
}
}
}
// 修改代理处理器以支持获取原始对象
/*
完整的 EntityProxyHandler
实现
*/
private class EntityProxyHandler implements IProxyHandler, java
.lang
.reflect
.InvocationHandler {
private final T original;
private final Map<String, Object> propertyValues = new HashMap<>
();
public EntityProxyHandler(T original) {
this.original = original;
cachePropertyValues
();
}
private void cachePropertyValues
() {
// 获取类信息
Class<?> clazz = original
.getClass();
// 遍历所有getter方法
for (Method method : clazz
.getMethods
()) {
String methodName = method
.getName
();
// 只处理getter方法
if (methodName
.startsWith("get") && !methodName
.equals("
getClass")
&& method
.getParameterTypes
().length == 0) {
try {
// 获取属性名（去掉"get"并将首字母小写）
String propertyName = methodName
.substring(3);
propertyName = Character
.toLowerCase(propertyName
.charAt(0)) + propertyName
.substring(1);
// 调用getter获取值
Object value = method
.invoke(original);
propertyValues
.put(propertyName, value);
} catch (Exception e) {
Log
.e("Wrapper", "Failed to cache property " + methodName, e);
}
}
}
}
@Override
public T getOriginal
() {
return original;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
String methodName = method
.getName
();
// 只拦截setter方法
if (methodName
.startsWith("set") && args != null && args
.length == 1) {
String propertyName = methodName
.substring(3);
propertyName = Character
.toLowerCase(propertyName
.charAt(0)) + propertyName
.substring(1);
Object oldValue = propertyValues
.get(propertyName);
Object newValue = args[0];
// 如果值未改变，不触发同步
if (Objects
.equals(oldValue, newValue)) {
return null;
}
// 调用原始对象的setter方法
Method setter = original
.getClass().getMethod(methodName, newValue
.getClass());
setter
.invoke(original, newValue);
// 更新属性缓存
propertyValues
.put(propertyName, newValue);
// 触发属性变更监听
firePropertyChange(original, propertyName, oldValue, newValue);
// 非批量模式下自动同步
if (!batchMode) {
syncEntity(original);
}
}
// 其他接口方法直接调用原始对象
return method
.invoke(original, args);
}
private Object getPropertyValue(String propertyName) {
String getterName = "get" + propertyName
.substring(0, 1)
.toUpperCase
() + propertyName
.substring(1);
try {
Method getter = original
.getClass().getMethod(getterName);
return getter
.invoke(original);
} catch (Exception e) {
Log
.e("ProxyHandler", "Failed to get property value: " + propertyName, e);
return null;
}
}
}
// 在 SynchronizedList 类中添加
private interface IProxyHandler {
Object getOriginal
();
}
}package com
.example
.kucun2
.entity
.data;
import android
.content
.Context;
import android
.util
.Log;
import androidx
.annotation
.NonNull;
import com
.example
.kucun2
.entity
.;
import com
.example
.kucun2
.entity
.data
.SynchronizableEntity;
import com
.example
.kucun2
.entity
.data
.SynchronizedList;
import com
.google
.gson
.Gson;
import com
.google
.gson
.reflect
.TypeToken;
import okhttp3
.;
import org
.json
.JSONObject;
import java
.io
.IOException;
import java
.lang
.reflect
.Type;
import java
.util
.HashMap;
import java
.util
.Map;
import java
.util
.concurrent
.TimeUnit;
public class AppDataManager {
private final Context context;
private final OkHttpClient httpClient;
private final Gson gson;
private Map<String, SynchronizedList<? extends SynchronizableEntity>> dataCache;
private static final String BASE_URL = “https://tian
.sef/Kucun2”;
private static final String API_ALL = “/app/all”;
public AppDataManager(Context context) {
this.context = context;
this.gson = new Gson
();
this.dataCache = new HashMap<>
();
this.httpClient = new OkHttpClient
.Builder
()
.connectTimeout(15, TimeUnit
.SECONDS)
.readTimeout(30, TimeUnit
.SECONDS)
.build
();
}
/**
* 从服务器加载完整数据集
*/
public void loadFullDataset(DataCallback callback) {
Request request = new Request
.Builder
()
.url(BASE_URL + API_ALL)
.build
();
httpClient
.newCall(request)
.enqueue(new Callback
() {
@Override
public void onFailure(@NonNull Call call, @NonNull IOException e) {
Log
.e("AppDataManager", "Failed to load full dataset", e);
callback
.onFailure("Network error: " + e
.getMessage
());
}
@Override
public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
if (!response
.isSuccessful
()) {
callback
.onFailure("HTTP error: " + response
.code
());
return;
}
try {
String jsonData = response
.body
().string
();
JSONObject jsonObject = new JSONObject(jsonData);
JSONObject data = jsonObject
.getJSONObject("data");
// 解析各实体列表
parseEntityList(data, "bancais", Bancai
.class);
parseEntityList(data, "dingdans", Dingdan
.class);
parseEntityList(data, "mupis", Mupi
.class);
parseEntityList(data, "chanpins", Chanpin
.class);
parseEntityList(data, "kucuns", Kucun
.class);
parseEntityList(data, "chanpin_zujians", Chanpin_Zujian
.class);
parseEntityList(data, "zujians", Zujian
.class);
parseEntityList(data, "caizhis", Caizhi
.class);
parseEntityList(data, "users", User
.class);
callback
.onSuccess
();
} catch (Exception e) {
Log
.e("AppDataManager", "Error parsing response", e);
callback
.onFailure("Parsing error: " + e
.getMessage
());
}
}
});
}
/**
* 解析实体列表
*/
private <T extends SynchronizableEntity> void parseEntityList(JSONObject data, String key, Class<T> clazz) {
try {
Type listType = TypeToken
.getParameterized(SynchronizedList
.class, clazz)
.getType
();
SynchronizedList<T> list = gson
.fromJson(data
.getString(key), listType);
dataCache
.put(key, list);
} catch (Exception e) {
Log
.e("AppDataManager", "Failed to parse " + key, e);
}
}
/**
* 添加实体到特定集合
*/
public <T extends SynchronizableEntity> void addEntity(T entity, Class<T> clazz, DataCallback callback) {
String endpoint = BASE_URL + getAddEndpointForClass(clazz);
RequestBody body = RequestBody
.create(
gson
.toJson(entity),
MediaType
.parse("application/json")
);
Request request = new Request
.Builder
()
.url(endpoint)
.post(body)
.build
();
httpClient
.newCall(request)
.enqueue(new Callback
() {
@Override
public void onFailure(@NonNull Call call, @NonNull IOException e) {
Log
.e("AppDataManager", "Add entity failed", e);
callback
.onFailure("Network error: " + e
.getMessage
());
}
@Override
public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
if (response
.isSuccessful
()) {
try {
T newEntity = gson
.fromJson(response
.body
().string
(), clazz);
SynchronizedList<T> list = (SynchronizedList<T>) dataCache
.get(getCacheKeyForClass(clazz));
if (list != null) {
list
.add(newEntity);
}
callback
.onSuccess
();
} catch (Exception e) {
callback
.onFailure("Parsing error: " + e
.getMessage
());
}
} else {
callback
.onFailure("API error: " + response
.code
());
}
}
});
}
/**
* 获取添加操作的API端点
*/
private <T> String getAddEndpointForClass(Class<T> clazz) {
// 基于简单的命名约定生成端点
String className = clazz
.getSimpleName
().toLowerCase
();
return "/app/" + className + "/add";
}
/**
* 获取缓存键名
*/
private <T> String getCacheKeyForClass(Class<T> clazz) {
return clazz
.getSimpleName
().toLowerCase
() + "s";
}
/**
* 从缓存获取实体列表
*/
@SuppressWarnings("unchecked")
public <T extends SynchronizableEntity> SynchronizedList<T> getEntityList(Class<T> clazz) {
String key = getCacheKeyForClass(clazz);
return (SynchronizedList<T>) dataCache
.get(key);
}
/**
* 类型安全的实体更新方法
* @param entity 要更新的实体
* @param callback 操作回调
*/
@SuppressWarnings("unchecked")
public <T extends SynchronizableEntity> void updateEntity(T entity, DataCallback callback) {
// 使用实体类的实际类型
Class<T> entityClass = (Class<T>) entity
.getClass();
updateEntity(entity, entityClass, callback);
}
/**
* 更新实体
*/
public <T extends SynchronizableEntity> void updateEntity(T entity, Class<T> clazz, DataCallback callback) {
String endpoint = BASE_URL + getUpdateEndpointForClass(clazz);
RequestBody body = RequestBody
.create(
gson
.toJson(entity),
MediaType
.parse("application/json")
);
Request request = new Request
.Builder
()
.url(endpoint)
.put(body)
.build
();
httpClient
.newCall(request)
.enqueue(new Callback
() {
@Override
public void onFailure(@NonNull Call call, @NonNull IOException e) {
callback
.onFailure("Network error: " + e
.getMessage
());
}
@Override
public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
if (response
.isSuccessful
()) {
callback
.onSuccess
();
} else {
callback
.onFailure("API error: " + response
.code
());
}
}
});
}
/**
* 获取更新操作的API端点
*/
private <T> String getUpdateEndpointForClass(Class<T> clazz) {
// 基于简单命名约定生成端点
String className = clazz
.getSimpleName
().toLowerCase
();
return "/app/" + className + "/update";
}
/**
* 获取用户认证令牌
*/
public void authenticateUser(String username, String password, AuthCallback callback) {
JSONObject authJson = new JSONObject
();
try {
authJson
.put("username", username);
authJson
.put("password", password);
} catch (Exception e) {
callback
.onFailure("Auth parameter error");
return;
}
RequestBody body = RequestBody
.create(
authJson
.toString
(),
MediaType
.parse("application/json")
);
Request request = new Request
.Builder
()
.url(BASE_URL + "/user/login")
.post(body)
.build
();
httpClient
.newCall(request)
.enqueue(new Callback
() {
@Override
public void onFailure(@NonNull Call call, @NonNull IOException e) {
callback
.onFailure("Network error: " + e
.getMessage
());
}
@Override
public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
if (response
.isSuccessful
()) {
try {
JSONObject authResponse = new JSONObject(response
.body
().string
());
String token = authResponse
.getString("token");
callback
.onSuccess(token);
} catch (Exception e) {
callback
.onFailure("Token parsing error");
}
} else {
callback
.onFailure("Authentication failed");
}
}
});
}
/**
* 数据加载回调接口
*/
public interface DataCallback {
void onSuccess
();
void onFailure(String error);
}
/**
* 认证回调接口
*/
public interface AuthCallback {
void onSuccess(String token);
void onFailure(String error);
}
} E FATAL EXCEPTION: main
Process: com
.example
.kucun2, PID: 31140
java
.lang
.NullPointerException: Parameter specified as non-null is null: method okhttp3
.Request$Builder
.url, parameter url
at okhttp3
.Request$Builder
.url(Unknown Source:2)
at com
.example
.kucun2
.entity
.data
.SynchronizedList
.syncEntity(SynchronizedList
.java:114)
at com
.example
.kucun2
.entity
.data
.SynchronizedList
.add(SynchronizedList
.java:272)
at com
.example
.kucun2
.ui
.jinhuo
.AddInventoryFragment
.createAndSaveDingdan(AddInventoryFragment
.java:445)
at com
.example
.kucun2
.ui
.jinhuo
.AddInventoryFragment
.lambda$showNewDingdanDialog$8(AddInventoryFragment
.java:423)
at com
.example
.kucun2
.ui
.jinhuo
.AddInventoryFragment
.$r8$lambda$viLBw5kNmkDSVG17JoXzuH5G85E(Unknown Source:0)
at com
.example
.kucun2
.ui
.jinhuo
.AddInventoryFragment$$ExternalSyntheticLambda20
.onClick(D8$$SyntheticClass:0)
at com
.android
.internal
.app
.AlertController$ButtonHandler
.handleMessage(AlertController
.java:250)
at android
.os
.Handler
.dispatchMessage(Handler
.java:109)
at android
.os
.Looper
.loopOnce(Looper
.java:250)
at android
.os
.Looper
.loop(Looper
.java:340)
本文详细探讨了Java Null Pointer Exception的常见原因，如未初始化的字符串、接口对象的初始化、空值判断等，并提供了异常分布结构图和避免异常的方法，包括使用String.valueOf()和实例化null对象。
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