Okhttp当request body为空null时报method POST must have a request body错误的解决办法

本文介绍了解决Postman中发送空请求体时遇到的编译错误问题,提供了具体的代码示例,通过创建一个空的RequestBody来避免Post方法必须包含请求体的限制。

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postman自动给出的代码如下,如果requestBody为空的时候,此时编译器会报错

.post(null)
  .addHeader("Cookie", *********

报错如下
java.lang.IllegalArgumentException: method POST must have a request body. at com.squareup.okhttp.Request$Builder.method(Request.java:244)
解决办法:

RequestBody body =RequestBody.create(null, new byte[0]);
		Request request = new Request.Builder()
		  .url("www.****")
		  .post(body)
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.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 SynchronizableEntity> 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); 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; // 确保代理对象实现原始对象的所有接口+目标接口 Class<?>[] interfaces = new Class<?>[]{ SynchronizableEntity.class, // 强制实现目标接口 entityClass // 实体类或接口 }; return (T) Proxy.newProxyInstance( original.getClass().getClassLoader(), interfaces, 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; // 初始化属性缓存 for (Method method : original.getClass().getMethods()) { if (method.getName().startsWith("get") && method.getParameterCount() == 0) { try { String propName = method.getName().substring(3); propName = Character.toLowerCase(propName.charAt(0)) + propName.substring(1); propertyValues.put(propName, method.invoke(original)); } catch (Exception e) { Log.e("ProxyHandler", "Failed to cache property", e); } } } } @Override public T getOriginal() { return original; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { String methodName = method.getName(); // 处理 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]; // 调用原始方法 Object result = method.invoke(original, args); propertyValues.put(propertyName, newValue); // 触发监听 firePropertyChange(original, propertyName, oldValue, newValue); // 非批量模式下自动同步 if (!batchMode) { syncEntity(original); } return result; } // 特殊处理 getOriginal 方法 if ("getOriginal".equals(methodName)) { return original; } // 处理 getter 方法(使用缓存) if (methodName.startsWith("get") && method.getParameterCount() == 0) { String propertyName = methodName.substring(3); propertyName = Character.toLowerCase(propertyName.charAt(0)) + propertyName.substring(1); return propertyValues.getOrDefault(propertyName, method.invoke(original)); } 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(); } } E FATAL EXCEPTION: main Process: com.example.kucun2, PID: 22195 java.lang.IllegalArgumentException: com.example.kucun2.entity.data.SynchronizableEntity is not an interface at java.lang.reflect.Proxy$ProxyClassFactory.apply(Proxy.java:635) at java.lang.reflect.Proxy$ProxyClassFactory.apply(Proxy.java:602) at java.lang.reflect.WeakCache$Factory.get(WeakCache.java:230) at java.lang.reflect.WeakCache.get(WeakCache.java:127) at java.lang.reflect.Proxy.getProxyClass0(Proxy.java:438) at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:873) at com.example.kucun2.entity.data.SynchronizedList.createProxy(SynchronizedList.java:186) at com.example.kucun2.entity.data.SynchronizedList.add(SynchronizedList.java:263) at com.example.kucun2.ui.jinhuo.AddInventoryFragment.createAndSaveDingdan(AddInventoryFragment.java:445) at com.example.kucun2.ui.jinhuo.AddInventoryFragment.lambda$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$ButtonHandler.handleMessage(AlertController.java:250) at android.os.Handler.dispatchMessage(Handler.java:109) at android.os.Looper.loopOnce(Looper.java:250) at android.os.Looper.loop(Looper.java:340) at android.app.ActivityThread.main(ActivityThread.java:9913) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:621) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:957)
最新发布
06-10
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