聊聊Spring AI的Prompt

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本文主要研究一下Spring AI的Prompt

Prompt

org/springframework/ai/chat/prompt/Prompt.java

public class Prompt implements ModelRequest<List<Message>> {private final List<Message> messages;private ChatOptions chatOptions;public Prompt(String contents) {this(new UserMessage(contents));}public Prompt(Message message) {this(Collections.singletonList(message));}public Prompt(List<Message> messages) {this(messages, null);}public Prompt(Message... messages) {this(Arrays.asList(messages), null);}public Prompt(String contents, ChatOptions chatOptions) {this(new UserMessage(contents), chatOptions);}public Prompt(Message message, ChatOptions chatOptions) {this(Collections.singletonList(message), chatOptions);}public Prompt(List<Message> messages, ChatOptions chatOptions) {this.messages = messages;this.chatOptions = chatOptions;}public String getContents() {StringBuilder sb = new StringBuilder();for (Message message : getInstructions()) {sb.append(message.getText());}return sb.toString();}//......
}	

Prompt实现了ModelRequest方法，其getInstructions返回的类型为List<Message>，其getContents方法遍历getInstructions添加message.getText()

Message

org/springframework/ai/chat/messages/Message.java

public interface Message extends Content {/*** Get the message type.* @return the message type*/MessageType getMessageType();}

MessageType

org/springframework/ai/chat/messages/MessageType.java

public enum MessageType {/*** A {@link Message} of type {@literal user}, having the user role and originating* from an end-user or developer.* @see UserMessage*/USER("user"),/*** A {@link Message} of type {@literal assistant} passed in subsequent input* {@link Message Messages} as the {@link Message} generated in response to the user.* @see AssistantMessage*/ASSISTANT("assistant"),/*** A {@link Message} of type {@literal system} passed as input {@link Message* Messages} containing high-level instructions for the conversation, such as behave* like a certain character or provide answers in a specific format.* @see SystemMessage*/SYSTEM("system"),/*** A {@link Message} of type {@literal function} passed as input {@link Message* Messages} with function content in a chat application.* @see ToolResponseMessage*/TOOL("tool");private final String value;MessageType(String value) {this.value = value;}public static MessageType fromValue(String value) {for (MessageType messageType : MessageType.values()) {if (messageType.getValue().equals(value)) {return messageType;}}throw new IllegalArgumentException("Invalid MessageType value: " + value);}public String getValue() {return this.value;}}

MessageType定义了USER、SYSTEM、ASSISTANT、TOOL这几种类型

PromptTemplate

PromptTemplateMessageActions

org/springframework/ai/chat/prompt/PromptTemplateMessageActions.java

public interface PromptTemplateMessageActions {Message createMessage();Message createMessage(List<Media> mediaList);Message createMessage(Map<String, Object> model);}

PromptTemplateMessageActions定义了createMessage方法

PromptTemplateStringActions

org/springframework/ai/chat/prompt/PromptTemplateStringActions.java

public interface PromptTemplateStringActions {String render();String render(Map<String, Object> model);}

PromptTemplateStringActions定义了render方法，渲染为String类型

PromptTemplateChatActions

org/springframework/ai/chat/prompt/PromptTemplateChatActions.java

public interface PromptTemplateChatActions {List<Message> createMessages();List<Message> createMessages(Map<String, Object> model);}

PromptTemplateChatActions接口定义了createMessages方法，返回List<Message>

PromptTemplateActions

org/springframework/ai/chat/prompt/PromptTemplateActions.java

public interface PromptTemplateActions extends PromptTemplateStringActions {Prompt create();Prompt create(ChatOptions modelOptions);Prompt create(Map<String, Object> model);Prompt create(Map<String, Object> model, ChatOptions modelOptions);}

PromptTemplateActions继承了PromptTemplateStringActions接口，它定义了create方法，用于创建Prompt

PromptTemplate

public class PromptTemplate implements PromptTemplateActions, PromptTemplateMessageActions {protected String template;protected TemplateFormat templateFormat = TemplateFormat.ST;private ST st;private Map<String, Object> dynamicModel = new HashMap<>();//......// Render Methods@Overridepublic String render() {validate(this.dynamicModel);return this.st.render();}@Overridepublic String render(Map<String, Object> model) {validate(model);for (Entry<String, Object> entry : model.entrySet()) {if (this.st.getAttribute(entry.getKey()) != null) {this.st.remove(entry.getKey());}if (entry.getValue() instanceof Resource) {this.st.add(entry.getKey(), renderResource((Resource) entry.getValue()));}else {this.st.add(entry.getKey(), entry.getValue());}}return this.st.render();}@Overridepublic Message createMessage() {return new UserMessage(render());}@Overridepublic Message createMessage(List<Media> mediaList) {return new UserMessage(render(), mediaList);}@Overridepublic Message createMessage(Map<String, Object> model) {return new UserMessage(render(model));}@Overridepublic Prompt create() {return new Prompt(render(new HashMap<>()));}@Overridepublic Prompt create(ChatOptions modelOptions) {return new Prompt(render(new HashMap<>()), modelOptions);}@Overridepublic Prompt create(Map<String, Object> model) {return new Prompt(render(model));}@Overridepublic Prompt create(Map<String, Object> model, ChatOptions modelOptions) {return new Prompt(render(model), modelOptions);}//......		
}	

PromptTemplate实现了PromptTemplateActions、PromptTemplateMessageActions接口，其render使用了org.stringtemplate.v4.ST来渲染。
PromptTemplateStringActions专注于创建和渲染提示字符串，代表了提示生成的最基本形式。
PromptTemplateMessageActions专为通过生成和操作Message对象来创建提示而设计。
PromptTemplateActions旨在返回Prompt对象，该对象可以传递给ChatModel以生成响应。

SystemPromptTemplate

org/springframework/ai/chat/prompt/SystemPromptTemplate.java

public class SystemPromptTemplate extends PromptTemplate {public SystemPromptTemplate(String template) {super(template);}public SystemPromptTemplate(Resource resource) {super(resource);}@Overridepublic Message createMessage() {return new SystemMessage(render());}@Overridepublic Message createMessage(Map<String, Object> model) {return new SystemMessage(render(model));}@Overridepublic Prompt create() {return new Prompt(new SystemMessage(render()));}@Overridepublic Prompt create(Map<String, Object> model) {return new Prompt(new SystemMessage(render(model)));}}

SystemPromptTemplate继承了PromptTemplate，其createMessage返回的是SystemMessage

FunctionPromptTemplate

org/springframework/ai/chat/prompt/FunctionPromptTemplate.java

public class FunctionPromptTemplate extends PromptTemplate {private String name;public FunctionPromptTemplate(String template) {super(template);}}

FunctionPromptTemplate继承了PromptTemplate，它定义了一个name属性

ChatPromptTemplate

org/springframework/ai/chat/prompt/ChatPromptTemplate.java

public class ChatPromptTemplate implements PromptTemplateActions, PromptTemplateChatActions {private final List<PromptTemplate> promptTemplates;public ChatPromptTemplate(List<PromptTemplate> promptTemplates) {this.promptTemplates = promptTemplates;}@Overridepublic String render() {StringBuilder sb = new StringBuilder();for (PromptTemplate promptTemplate : this.promptTemplates) {sb.append(promptTemplate.render());}return sb.toString();}@Overridepublic String render(Map<String, Object> model) {StringBuilder sb = new StringBuilder();for (PromptTemplate promptTemplate : this.promptTemplates) {sb.append(promptTemplate.render(model));}return sb.toString();}@Overridepublic List<Message> createMessages() {List<Message> messages = new ArrayList<>();for (PromptTemplate promptTemplate : this.promptTemplates) {messages.add(promptTemplate.createMessage());}return messages;}@Overridepublic List<Message> createMessages(Map<String, Object> model) {List<Message> messages = new ArrayList<>();for (PromptTemplate promptTemplate : this.promptTemplates) {messages.add(promptTemplate.createMessage(model));}return messages;}@Overridepublic Prompt create() {List<Message> messages = createMessages();return new Prompt(messages);}@Overridepublic Prompt create(ChatOptions modelOptions) {List<Message> messages = createMessages();return new Prompt(messages, modelOptions);}@Overridepublic Prompt create(Map<String, Object> model) {List<Message> messages = createMessages(model);return new Prompt(messages);}@Overridepublic Prompt create(Map<String, Object> model, ChatOptions modelOptions) {List<Message> messages = createMessages(model);return new Prompt(messages, modelOptions);}}

ChatPromptTemplate实现了PromptTemplateActions, PromptTemplateChatActions接口，其构造器输入promptTemplates，其render方法遍历promptTemplates，挨个添加promptTemplate.render()；其createMessages方法遍历promptTemplates，挨个添加promptTemplate.createMessage()

AssistantPromptTemplate

org/springframework/ai/chat/prompt/AssistantPromptTemplate.java

public class AssistantPromptTemplate extends PromptTemplate {public AssistantPromptTemplate(String template) {super(template);}public AssistantPromptTemplate(Resource resource) {super(resource);}@Overridepublic Prompt create() {return new Prompt(new AssistantMessage(render()));}@Overridepublic Prompt create(Map<String, Object> model) {return new Prompt(new AssistantMessage(render(model)));}@Overridepublic Message createMessage() {return new AssistantMessage(render());}@Overridepublic Message createMessage(Map<String, Object> model) {return new AssistantMessage(render(model));}}

AssistantPromptTemplate继承了PromptTemplate，其createMessage方法返回的是AssistantMessage

示例

PromptTemplate示例

PromptTemplate promptTemplate = new PromptTemplate("Tell me a {adjective} joke about {topic}");Prompt prompt = promptTemplate.create(Map.of("adjective", adjective, "topic", topic));return chatModel.call(prompt).getResult();

SystemPromptTemplate示例

String userText = """Tell me about three famous pirates from the Golden Age of Piracy and why they did.Write at least a sentence for each pirate.""";Message userMessage = new UserMessage(userText);String systemText = """You are a helpful AI assistant that helps people find information.Your name is {name}You should reply to the user's request with your name and also in the style of a {voice}.""";SystemPromptTemplate systemPromptTemplate = new SystemPromptTemplate(systemText);
Message systemMessage = systemPromptTemplate.createMessage(Map.of("name", name, "voice", voice));Prompt prompt = new Prompt(List.of(userMessage, systemMessage));List<Generation> response = chatModel.call(prompt).getResults();

小结

Spring AI的Message定义了MessageType属性，它有USER、SYSTEM、ASSISTANT、TOOL这几种类型；PromptTemplate的createMessage方法返回的是UserMessage，SystemPromptTemplate的createMessage方法返回的是SystemMessage，AssistantPromptTemplate的createMessage方法返回的是AssistantMessage。SystemPromptTemplate及AssistantPromptTemplate都继承了PromptTemplate，其render方法使用了org.stringtemplate.v4.ST来渲染；ChatPromptTemplate则是聚合了一系列的promptTemplates。

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