首页 > 应用开发 > IT综合 > 大语言模型应用开发指南:从原理到实践的完整流程
# 大语言模型应用开发指南:从原理到实践的完整流程
## 大语言模型基础架构与工作原理
大语言模型(LLM)基于Transformer架构,通过自注意力机制处理序列数据,实现了对自然语言的深度理解与生成能力。
```python
# Transformer自注意力机制简化实现
import torch
import torch.nn as nn
import torch.nn.functional as F
class MultiHeadAttention(nn.Module):
def __init__(self, d_model, num_heads):
super().__init__()
self.num_heads = num_heads
self.d_model = d_model
assert d_model % num_heads == 0
self.d_k = d_model // num_heads
self.q_linear = nn.Linear(d_model, d_model)
self.k_linear = nn.Linear(d_model, d_model)
self.v_linear = nn.Linear(d_model, d_model)
self.out_linear = nn.Linear(d_model, d_model)
def forward(self, q, k, v, mask=None):
batch_size = q.size(0)
# 线性变换并分割为多头
q = self.q_linear(q).view(batch_size, -1, self.num_heads, self.d_k).transpose(1, 2)
k = self.k_linear(k).view(batch_size, -1, self.num_heads, self.d_k).transpose(1, 2)
v = self.v_linear(v).view(batch_size, -1, self.num_heads, self.d_k).transpose(1, 2)
# 计算注意力分数
scores = torch.matmul(q, k.transpose(-2, -1)) / (self.d_k ** 0.5)
if mask is not None:
scores = scores.masked_fill(mask == 0, -1e9)
# 注意力权重
attn_weights = F.softmax(scores, dim=-1)
# 上下文向量
context = torch.matmul(attn_weights, v)
# 合并多头输出
context = context.transpose(1, 2).contiguous().view(batch_size, -1, self.d_model)
output = self.out_linear(context)
return output, attn_weights
# 使用预训练模型进行基础推理
from transformers import AutoTokenizer, AutoModelForCausalLM
class BaseLLMInference:
def __init__(self, model_name="gpt2"):
self.tokenizer = AutoTokenizer.from_pretrained(model_name)
self.model = AutoModelForCausalLM.from_pretrained(model_name)
# 设置填充token
if self.tokenizer.pad_token is None:
self.tokenizer.pad_token = self.tokenizer.eos_token
def generate_text(self, prompt, max_length=100, temperature=0.7):
inputs = self.tokenizer(prompt, return_tensors="pt")
with torch.no_grad():
outputs = self.model.generate(
inputs.input_ids,
max_length=max_length,
temperature=temperature,
do_sample=True,
pad_token_id=self.tokenizer.pad_token_id,
eos_token_id=self.tokenizer.eos_token_id
)
generated_text = self.tokenizer.decode(outputs[0], skip_special_tokens=True)
return generated_text
```
## LLM应用开发完整流程
### 1. 需求分析与任务定义
```python
# 任务定义示例:智能客服系统
from dataclasses import dataclass
from enum import Enum
class TaskType(Enum):
CLASSIFICATION = "classification"
GENERATION = "generation"
SUMMARIZATION = "summarization"
TRANSLATION = "translation"
CODE_GENERATION = "code_generation"
@dataclass
class TaskDefinition:
task_type: TaskType
domain: str
input_format: str
output_format: str
success_metrics: dict
constraints: dict
# 定义智能客服任务
customer_service_task = TaskDefinition(
task_type=TaskType.CLASSIFICATION,
domain="电商客服",
input_format="用户问题文本",
output_format="{'intent': '意图类别', 'response': '回复文本'}",
success_metrics={
'accuracy': 0.95,
'response_time': 2.0, # 秒
'user_satisfaction': 4.5 # 5分制
},
constraints={
'max_response_length': 200,
'supported_languages': ['zh', 'en'],
'sensitive_info_filter': True
}
)
# 数据需求分析
@dataclass
class DataRequirement:
min_samples: int
data_types: list
annotation_requirements: dict
quality_standards: dict
cs_data_requirement = DataRequirement(
min_samples=10000,
data_types=['customer_queries', 'agent_responses', 'conversation_logs'],
annotation_requirements={
'intent_labels': ['退货', '换货', '咨询', '投诉', '物流查询'],
'emotion_labels': ['positive', 'neutral', 'negative']
},
quality_standards={
'accuracy_threshold': 0.98,
'consistency_check': True
}
)
```
### 2. 数据准备与处理
```python
# 数据收集与清洗管道
import pandas as pd
import numpy as np
from typing import List, Dict
import re
class DataPipeline:
def __init__(self):
self.processors = []
def add_processor(self, processor):
self.processors.append(processor)
def process(self, data):
for processor in self.processors:
data = processor(data)
return data
class TextCleaner:
"""文本清洗处理器"""
@staticmethod
def remove_special_chars(text):
# 移除特殊字符但保留标点
text = re.sub(r'[^\w\s\u4e00-\u9fff,.!?;:\'\"\-]', '', text)
return text
@staticmethod
def normalize_whitespace(text):
# 规范化空白字符
text = re.sub(r'\s+', ' ', text)
return text.strip()
@staticmethod
def remove_duplicates(texts):
# 移除重复文本
seen = set()
unique_texts = []
for text in texts:
if text not in seen:
seen.add(text)
unique_texts.append(text)
return unique_texts
# 数据增强策略
import nlpaug.augmenter.word as naw
class DataAugmenter:
def __init__(self):
# 同义词替换增强
self.synonym_aug = naw.SynonymAug(aug_src='wordnet')
# 回译增强
self.back_translation_aug = naw.BackTranslationAug(
from_model_name='facebook/wmt19-en-de',
to_model_name='facebook/wmt19-de-en'
)
def augment_dataset(self, texts, labels, augmentation_factor=2):
augmented_texts = []
augmented_labels = []
for text, label in zip(texts, labels):
augmented_texts.append(text)
augmented_labels.append(label)
# 同义词替换增强
syn_text = self.synonym_aug.augment(text)
augmented_texts.append(syn_text)
augmented_labels.append(label)
# 回译增强
if augmentation_factor > 2:
bt_text = self.back_translation_aug.augment(text)
augmented_texts.append(bt_text)
augmented_labels.append(label)
return augmented_texts, augmented_labels
# 数据集构建
from datasets import Dataset, DatasetDict
class DatasetBuilder:
def __init__(self, tokenizer):
self.tokenizer = tokenizer
def create_dataset(self, texts, labels, test_size=0.2):
# 创建训练和测试集
df = pd.DataFrame({'text': texts, 'label': labels})
# 划分数据集
from sklearn.model_selection import train_test_split
train_df, test_df = train_test_split(df, test_size=test_size, stratify=df['label'])
# 转换为HuggingFace Dataset格式
train_dataset = Dataset.from_pandas(train_df)
test_dataset = Dataset.from_pandas(test_df)
dataset = DatasetDict({
'train': train_dataset,
'test': test_dataset
})
return dataset
def tokenize_dataset(self, dataset, max_length=128):
def tokenize_function(examples):
return self.tokenizer(
examples['text'],
truncation=True,
padding='max_length',
max_length=max_length
)
tokenized_dataset = dataset.map(tokenize_function, batched=True)
return tokenized_dataset
```
### 3. 模型选择与微调
```python
# 模型选择策略
from transformers import (
AutoModelForSequenceClassification,
AutoModelForTokenClassification,
AutoModelForSeq2SeqLM,
TrainingArguments,
Trainer
)
class ModelSelector:
def __init__(self, task_type):
self.task_type = task_type
self.model_registry = self._build_registry()
def _build_registry(self):
# 模型注册表:根据不同任务推荐模型
registry = {
'classification': {
'zh': 'bert-base-chinese',
'en': 'bert-base-uncased',
'multilingual': 'xlm-roberta-base'
},
'generation': {
'zh': 'uer/gpt2-chinese-cluecorpussmall',
'en': 'gpt2',
'multilingual': 'facebook/mbart-large-50'
},
'summarization': {
'zh': 'csebuetnlp/mT5_multilingual_XLSum',
'en': 'facebook/bart-large-cnn',
'multilingual': 'google/mt5-base'
}
}
return registry
def select_model(self, language='zh', model_size='base'):
task_models = self.model_registry.get(self.task_type, {})
model_name = task_models.get(language, task_models.get('multilingual'))
if model_size == 'large' and 'base' in model_name:
model_name = model_name.replace('base', 'large')
return model_name
# 模型微调配置
class FineTuningConfig:
def __init__(self, task_type, dataset_size):
self.task_type = task_type
self.dataset_size = dataset_size
self._configure()
def _configure(self):
# 根据任务类型和数据量配置训练参数
if self.task_type == 'classification':
self.config = {
'learning_rate': 2e-5,
'num_train_epochs': 3,
'per_device_train_batch_size': 16,
'per_device_eval_batch_size': 32,
'warmup_steps': 500,
'weight_decay': 0.01,
'logging_steps': 100,
'eval_steps': 500,
'save_steps': 1000
}
elif self.task_type == 'generation':
self.config = {
'learning_rate': 5e-5,
'num_train_epochs': 5,
'per_device_train_batch_size': 8,
'gradient_accumulation_steps': 4,
'warmup_steps': 1000,
'weight_decay': 0.01,
'logging_steps': 50,
'predict_with_generate': True
}
# 根据数据量调整
if self.dataset_size < 1000:
self.config['num_train_epochs'] = 10
self.config['learning_rate'] = 3e-5
elif self.dataset_size > 10000:
self.config['num_train_epochs'] = 2
self.config['learning_rate'] = 1e-5
# 模型微调实现
class ModelFineTuner:
def __init__(self, model_name, tokenizer, task_type):
self.model_name = model_name
self.tokenizer = tokenizer
self.task_type = task_type
self._load_model()
def _load_model(self):
if self.task_type == 'classification':
self.model = AutoModelForSequenceClassification.from_pretrained(
self.model_name,
num_labels=5 # 假设5个类别
)
elif self.task_type == 'generation':
self.model = AutoModelForCausalLM.from_pretrained(self.model_name)
def fine_tune(self, train_dataset, eval_dataset, config):
# 训练参数
training_args = TrainingArguments(
output_dir=f"./results/{self.model_name}",
**config.config
)
# 数据整理器
from transformers import DataCollatorWithPadding
data_collator = DataCollatorWithPadding(tokenizer=self.tokenizer)
# 创建Trainer
trainer = Trainer(
model=self.model,
args=training_args,
train_dataset=train_dataset,
eval_dataset=eval_dataset,
data_collator=data_collator,
tokenizer=self.tokenizer
)
# 开始训练
trainer.train()
# 评估模型
eval_results = trainer.evaluate()
print(f"评估结果: {eval_results}")
return trainer
```
### 4. 提示工程与优化
```python
# 提示工程框架
from typing import List, Dict, Any
class PromptEngineer:
def __init__(self):
self.prompt_templates = {}
self.few_shot_examples = {}
def register_template(self, task_name, template):
self.prompt_templates[task_name] = template
def register_examples(self, task_name, examples):
self.few_shot_examples[task_name] = examples
def build_prompt(self, task_name, input_data, num_examples=3):
template = self.prompt_templates.get(task_name, "")
examples = self.few_shot_examples.get(task_name, [])
# 构建few-shot示例部分
examples_text = ""
if examples and num_examples > 0:
selected_examples = examples[:num_examples]
for example in selected_examples:
examples_text += f"输入: {example['input']}\n输出: {example['output']}\n\n"
# 替换模板中的变量
prompt = template.format(
examples=examples_text,
input=input_data
)
return prompt
# 定义各种任务的提示模板
prompt_engineer = PromptEngineer()
# 文本分类提示模板
prompt_engineer.register_template(
"text_classification",
"""请对以下文本进行分类:
{examples}
请分析以下文本并分类:
文本:{input}
分类结果:"""
)
# 代码生成提示模板
prompt_engineer.register_template(
"code_generation",
"""你是一个经验丰富的软件工程师。请根据要求编写代码。
要求:{input}
请用{language}语言编写代码:
```{language}
"""
)
# 注册few-shot示例
prompt_engineer.register_examples(
"sentiment_analysis",
[
{
"input": "这个产品质量很好,物超所值!",
"output": "正面"
},
{
"input": "服务态度很差,再也不会来了。",
"output": "负面"
},
{
"input": "产品一般般,没什么特别的。",
"output": "中性"
}
]
)
# 提示优化策略
class PromptOptimizer:
def __init__(self, llm_api):
self.llm_api = llm_api
def optimize_prompt(self, original_prompt, target_output, iterations=3):
best_prompt = original_prompt
best_score = 0
for i in range(iterations):
# 生成多个变体
variants = self._generate_variants(best_prompt)
# 测试每个变体
scores = []
for variant in variants:
output = self.llm_api.generate(variant)
score = self._evaluate_output(output, target_output)
scores.append((variant, score))
# 选择最佳变体
scores.sort(key=lambda x: x[1], reverse=True)
best_variant, best_variant_score = scores[0]
if best_variant_score > best_score:
best_prompt = best_variant
best_score = best_variant_score
return best_prompt, best_score
def _generate_variants(self, prompt):
# 生成提示的多种变体
variants = []
# 变体1:添加角色设定
variants.append(f"你是一个专家。{prompt}")
# 变体2:添加格式要求
variants.append(f"{prompt}\n请用清晰的步骤回答。")
# 变体3:添加思维链要求
variants.append(f"{prompt}\n请先思考,然后给出答案。")
return variants
def _evaluate_output(self, output, target):
# 简单相似度评估
from difflib import SequenceMatcher
return SequenceMatcher(None, output, target).ratio()
```
### 5. 评估与部署
```python
# 模型评估框架
from sklearn.metrics import accuracy_score, precision_score, recall_score, f1_score
import json
class ModelEvaluator:
def __init__(self, model, tokenizer):
self.model = model
self.tokenizer = tokenizer
def evaluate_classification(self, test_dataset):
<"pa.zhaiLimao.com"><"qa.yunruiwater.cn"><"ra.sxyicheng.cn">
predictions = []
labels = []
for example in test_dataset:
inputs = self.tokenizer(
example['text'],
return_tensors="pt",
truncation=True,
padding=True
)
with torch.no_grad():
outputs = self.model(**inputs)
pred = torch.argmax(outputs.logits, dim=-1)
predictions.append(pred.item())
labels.append(example['label'])
# 计算评估指标
metrics = {
'accuracy': accuracy_score(labels, predictions),
'precision': precision_score(labels, predictions, average='weighted'),
'recall': recall_score(labels, predictions, average='weighted'),
'f1_score': f1_score(labels, predictions, average='weighted')
}
return metrics
def evaluate_generation(self, test_dataset, reference_key='reference'):
from rouge_score import rouge_scorer
scorer = rouge_scorer.RougeScorer(['rouge1', 'rouge2', 'rougeL'], use_stemmer=True)
rouge_scores = []
for example in test_dataset:
generated = self.generate_text(example['text'])
reference = example[reference_key]
scores = scorer.score(reference, generated)
rouge_scores.append(scores)
# 计算平均ROUGE分数
avg_scores = {}
for key in ['rouge1', 'rouge2', 'rougeL']:
avg_scores[key] = {
'precision': np.mean([s[key].precision for s in rouge_scores]),
'recall': np.mean([s[key].recall for s in rouge_scores]),
'fmeasure': np.mean([s[key].fmeasure for s in rouge_scores])
}
return avg_scores
# 模型部署服务
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
import uvicorn
class LLMService:
def __init__(self, model_path):
self.model = AutoModelForCausalLM.from_pretrained(model_path)
self.tokenizer = AutoTokenizer.from_pretrained(model_path)
self.model.eval()
def predict(self, prompt, max_length=100):
inputs = self.tokenizer(prompt, return_tensors="pt")
with torch.no_grad():
outputs = self.model.generate(
inputs.input_ids,
max_length=max_length,
temperature=0.7,
do_sample=True
)
return self.tokenizer.decode(outputs[0], skip_special_tokens=True)
# FastAPI部署
app = FastAPI(title="LLM API服务")
class PredictionRequest(BaseModel):
prompt: str
max_length: int = 100
temperature: float = 0.7
class PredictionResponse(BaseModel):
generated_text: str
inference_time: float
# 加载模型
llm_service = LLMService("./fine_tuned_model")
@app.post("/predict", response_model=PredictionResponse)
async def predict(request: PredictionRequest):
try:
import time
start_time = time.time()
generated_text = llm_service.predict(
request.prompt,
max_length=request.max_length
)
inference_time = time.time() - start_time
return PredictionResponse(
generated_text=generated_text,
inference_time=inference_time
)
except Exception as e:
raise HTTPException(status_code=500, detail=str(e))
@app.get("/health")
async def health_check():
return {"status": "healthy"}
if __name__ == "__main__":
uvicorn.run(app, host="0.0.0.0", port=8000)
```
## 实战项目:智能文档助手
```python
# 智能文档助手完整实现
import os
from typing import List, Dict
import hashlib
class SmartDocumentAssistant:
def __init__(self, model_name="gpt2"):
self.model_name = model_name
self.vector_db = None # 向量数据库用于相似度搜索
self._initialize_components()
def _initialize_components(self):
# 初始化各种处理器
self.text_extractor = TextExtractor()
self.text_splitter = TextSplitter(chunk_size=500)
self.embedder = TextEmbedder()
self.llm = BaseLLMInference(self.model_name)
def process_documents(self, document_paths: List[str]):
"""处理文档集合"""
processed_docs = []
for path in document_paths:
# 提取文本
text = self.text_extractor.extract(path)
# 分块处理
chunks = self.text_splitter.split(text)
# 生成嵌入向量
embeddings = self.embedder.embed(chunks)
# 存储到向量数据库
self._store_to_vector_db(path, chunks, embeddings)
processed_docs.append({
'path': path,
'chunks': chunks,
'embeddings': embeddings
})
return processed_docs
def query_documents(self, question: str, top_k=3):
"""查询文档"""
# 查询向量数据库获取相关文档块
relevant_chunks = self.vector_db.search(question, top_k)
# 构建上下文
context = "\n".join([chunk['text'] for chunk in relevant_chunks])
# 构建提示
prompt = f"""基于以下文档内容回答问题:
文档内容:
{context}
问题:{question}
答案:"""
# 生成回答
answer = self.llm.generate_text(prompt)
return {
'answer': answer,
'sources': relevant_chunks,
'context': context
}
def summarize_document(self, document_path: str):
"""文档摘要"""
text = self.text_extractor.extract(document_path)
prompt = f"""请总结以下文档:
文档内容:
{text[:2000]} # 限制输入长度
总结:"""
summary = self.llm.generate_text(prompt, max_length=300)
return {
'summary': summary,
'original_length': len(text),
'summary_length': len(summary)
}
def translate_document(self, document_path: str, target_lang: str):
"""文档翻译"""
text = self.text_extractor.extract(document_path)
# 分块翻译(处理长文本)
chunks = self.text_splitter.split(text)
translated_chunks = []
for chunk in chunks:
prompt = f"""将以下文本翻译成{target_lang}:
原文:{chunk}
翻译:"""
translation = self.llm.generate_text(prompt)
translated_chunks.append(translation)
# 合并翻译结果
translated_text = "\n".join(translated_chunks)
return {
'original': text,
'translated': translated_text,
'target_language': target_lang
}
# 辅助类实现
class TextSplitter:
def __init__(self, chunk_size=500, overlap=50):
self.chunk_size = chunk_size
self.overlap = overlap
def split(self, text: str) -> List[str]:
"""按大小分割文本,保留重叠部分"""
<"sa.jsnjz.cn"><"ta.csxthr.com"><"ua.zhaiLimao.com">
chunks = []
start = 0
while start < len(text):
end = start + self.chunk_size
chunk = text[start:end]
chunks.append(chunk)
start = end - self.overlap
return chunks
class TextEmbedder:
def __init__(self, model_name="sentence-transformers/all-MiniLM-L6-v2"):
from sentence_transformers import SentenceTransformer
self.model = SentenceTransformer(model_name)
def embed(self, texts: List[str]):
"""生成文本嵌入向量"""
return self.model.encode(texts)
# 使用示例
def main():
# 初始化助手
assistant = SmartDocumentAssistant()
# 处理文档
document_paths = ["doc1.pdf", "doc2.docx", "doc3.txt"]
processed_docs = assistant.process_documents(document_paths)
# 查询文档
question = "什么是人工智能?"
result = assistant.query_documents(question)
print(f"问题: {question}")
print(f"回答: {result['answer']}")
# 生成摘要
summary = assistant.summarize_document("doc1.pdf")
print(f"\n文档摘要: {summary['summary']}")
# 翻译文档
translation = assistant.translate_document("doc2.docx", "英语")
print(f"\n翻译结果(前500字符): {translation['translated'][:500]}")
if __name__ == "__main__":
main()
```
## 性能优化与监控
```python
# 性能优化和监控系统
import time
import psutil
from prometheus_client import Counter, Gauge, Histogram, start_http_server
class LLMPerformanceMonitor:
def __init__(self, port=9090):
# 定义监控指标
self.request_counter = Counter('llm_requests_total', 'Total LLM requests')
self.error_counter = Counter('llm_errors_total', 'Total LLM errors')
self.latency_histogram = Histogram('llm_request_latency_seconds', 'Request latency')
self.memory_usage = Gauge('llm_memory_usage_bytes', 'Memory usage')
self.gpu_usage = Gauge('llm_gpu_usage_percent', 'GPU usage percentage')
# 启动监控服务器
start_http_server(port)
def track_request(self, func):
"""装饰器:跟踪函数执行"""
def wrapper(*args, **kwargs):
self.request_counter.inc()
start_time = time.time()
try:
result = func(*args, **kwargs)
latency = time.time() - start_time
self.latency_histogram.observe(latency)
return result
except Exception as e:
self.error_counter.inc()
raise e
finally:
# 更新内存使用情况
self.memory_usage.set(psutil.Process().memory_info().rss)
return wrapper
def generate_performance_report(self):
"""生成性能报告"""
import json
from datetime import datetime
report = {
'timestamp': datetime.now().isoformat(),
'total_requests': self.request_counter._value.get(),
'total_errors': self.error_counter._value.get(),
'memory_usage_mb': self.memory_usage._value.get() / (1024 * 1024),
'metrics': {}
}
return json.dumps(report, indent=2)
# 缓存优化
import redis
from functools import lru_cache
class LLMCache:
def __init__(self, redis_host='localhost', redis_port=6379):
self.redis_client = redis.Redis(host=redis_host, port=redis_port, decode_responses=True)
self.local_cache = {}
def _generate_cache_key(self, prompt, parameters):
"""生成缓存键"""
import hashlib
key_data = f"{prompt}:{parameters}"
return hashlib.md5(key_data.encode()).hexdigest()
@lru_cache(maxsize=1000)
def get_cached_response(self, prompt, parameters):
"""获取缓存的响应"""
cache_key = self._generate_cache_key(prompt, parameters)
# 先检查本地缓存
if cache_key in self.local_cache:
return self.local_cache[cache_key]
# 检查Redis缓存
cached_result = self.redis_client.get(cache_key)
if cached_result:
self.local_cache[cache_key] = cached_result
return cached_result
return None
def cache_response(self, prompt, parameters, response):
"""缓存响应"""
cache_key = self._generate_cache_key(prompt, parameters)
# 本地缓存
self.local_cache[cache_key] = response
# Redis缓存(设置过期时间)
self.redis_client.setex(cache_key, 3600, response) # 1小时过期
# 使用优化的LLM服务
class OptimizedLLMService:
def __init__(self, model_path, enable_cache=True, enable_monitoring=True):
self.model = AutoModelForCausalLM.from_pretrained(model_path)
self.tokenizer = AutoTokenizer.from_pretrained(model_path)
self.model.eval()
if enable_cache:
self.cache = LLMCache()
if enable_monitoring:
self.monitor = LLMPerformanceMonitor()
@monitor.track_request
def generate(self, prompt, max_length=100, temperature=0.7):
# 检查缓存
cache_key_params = f"{max_length}:{temperature}"
cached = self.cache.get_cached_response(prompt, cache_key_params)
if cached:
return cached
# 执行生成
inputs = self.tokenizer(prompt, return_tensors="pt")
with torch.no_grad():
outputs = self.model.generate(
inputs.input_ids,
max_length=max_length,
temperature=temperature,
do_sample=True
)
response = self.tokenizer.decode(outputs[0], skip_special_tokens=True)
# 缓存结果
self.cache.cache_response(prompt, cache_key_params, response)
return response
```
大语言模型应用开发是一个系统工程,需要综合考虑数据准备、模型选择、提示工程、性能优化等多个方面。通过遵循合理的开发流程,结合实际项目需求,可以构建出强大实用的LLM应用。持续的评估和优化是确保应用效果的关键。随着技术的不断发展,掌握这些核心开发技能将为构建下一代人工智能应用奠定坚实基础。
来自 “ ITPUB博客 ” ,链接:https://blog.itpub.net/19545/viewspace-3108954/ ,如需转载,请注明出处,否则将追究法律责任。