Add support for Elasticsearch vector store

vector-stores/spring-ai-elasticsearch-store/pom.xml

@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+		 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.ai</groupId>
+		<artifactId>spring-ai</artifactId>
+		<version>0.8.0-SNAPSHOT</version>
+		<relativePath>../../pom.xml</relativePath>
+	</parent>
+	<artifactId>spring-ai-elasticsearch-store</artifactId>
+	<packaging>jar</packaging>
+	<name>Spring AI Vector Store - Elasticsearch</name>
+	<description>Spring AI Elasticsearch Vector Store</description>
+	<url>https://github.com/spring-projects/spring-ai</url>
+
+	<scm>
+		<url>https://github.com/spring-projects/spring-ai</url>
+		<connection>git://github.com/spring-projects/spring-ai.git</connection>
+		<developerConnection>[email protected]:spring-projects/spring-ai.git</developerConnection>
+	</scm>
+
+	<properties>
+		<!-- testing -->
+		<hikari-cp.version>4.0.3</hikari-cp.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.ai</groupId>
+			<artifactId>spring-ai-core</artifactId>
+			<version>${parent.version}</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.elasticsearch.client</groupId>
+			<artifactId>elasticsearch-rest-client</artifactId>
+			<version>8.11.3</version>
+		</dependency>
+
+		<!-- TESTING -->
+		<dependency>
+			<groupId>org.springframework.ai</groupId>
+			<artifactId>spring-ai-openai</artifactId>
+			<version>${parent.version}</version>
+			<scope>test</scope>
+		</dependency>
+
+
+		<dependency>
+			<groupId>org.springframework.ai</groupId>
+			<artifactId>spring-ai-test</artifactId>
+			<version>${parent.version}</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>elasticsearch</artifactId>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>junit-jupiter</artifactId>
+			<version>${testcontainers.version}</version>
+			<scope>test</scope>
+		</dependency>
+
+	</dependencies>
+
+</project>

vector-stores/spring-ai-elasticsearch-store/src/main/java/org/springframework/ai/vectorstore/ElasticsearchAiSearchFilterExpressionConverter.java

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2023-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.vectorstore;
+
+import org.springframework.ai.vectorstore.filter.Filter;
+import org.springframework.ai.vectorstore.filter.Filter.Expression;
+import org.springframework.ai.vectorstore.filter.Filter.Key;
+import org.springframework.ai.vectorstore.filter.converter.AbstractFilterExpressionConverter;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.List;
+import java.util.TimeZone;
+import java.util.regex.Pattern;
+
+public class ElasticsearchAiSearchFilterExpressionConverter extends AbstractFilterExpressionConverter {
+
+    private static final Pattern DATE_FORMAT_PATTERN = Pattern.compile("\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z");
+
+    private final SimpleDateFormat dateFormat;
+
+    public ElasticsearchAiSearchFilterExpressionConverter() {
+        this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
+        this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+    }
+
+    @Override
+    protected void doExpression(Expression expression, StringBuilder context) {
+        if (expression.type() == Filter.ExpressionType.IN || expression.type() == Filter.ExpressionType.NIN) {
+            context.append(getOperationSymbol(expression));
+            context.append("(");
+            this.convertOperand(expression.left(), context);
+            this.convertOperand(expression.right(), context);
+            context.append(")");
+        } else {
+            this.convertOperand(expression.left(), context);
+            context.append(getOperationSymbol(expression));
+            this.convertOperand(expression.right(), context);
+        }
+    }
+
+    @Override
+    protected void doStartValueRange(Filter.Value listValue, StringBuilder context) {
+    }
+
+    @Override
+    protected void doEndValueRange(Filter.Value listValue, StringBuilder context) {
+    }
+
+    @Override
+    protected void doAddValueRangeSpitter(Filter.Value listValue, StringBuilder context) {
+        context.append(" OR ");
+    }
+
+    private String getOperationSymbol(Expression exp) {
+        return switch (exp.type()) {
+            case AND -> " AND ";
+            case OR -> " OR ";
+            case EQ, IN -> "";
+            case NE -> " NOT ";
+            case LT -> "<";
+            case LTE -> "<=";
+            case GT -> ">";
+            case GTE -> ">=";
+            case NIN -> "NOT ";
+            default -> throw new RuntimeException("Not supported expression type: " + exp.type());
+        };
+    }
+
+    @Override
+    public void doKey(Key key, StringBuilder context) {
+        var identifier = hasOuterQuotes(key.key()) ? removeOuterQuotes(key.key()) : key.key();
+        var prefixedIdentifier = withMetaPrefix(identifier);
+        context.append(prefixedIdentifier.trim()).append(":");
+    }
+
+    public String withMetaPrefix(String identifier) {
+        return "metadata." + identifier;
+    }
+
+    @Override
+    protected void doValue(Filter.Value filterValue, StringBuilder context) {
+        if (filterValue.value() instanceof List list) {
+            int c = 0;
+            for (Object v : list) {
+                context.append(v);
+                if (c++ < list.size() - 1) {
+                    this.doAddValueRangeSpitter(filterValue, context);
+                }
+            }
+        } else {
+            this.doSingleValue(filterValue.value(), context);
+        }
+    }
+
+    @Override
+    protected void doSingleValue(Object value, StringBuilder context) {
+        if (value instanceof Date date) {
+            context.append(this.dateFormat.format(date));
+        } else if (value instanceof String text) {
+            if (DATE_FORMAT_PATTERN.matcher(text).matches()) {
+                try {
+                    Date date = this.dateFormat.parse(text);
+                    context.append(this.dateFormat.format(date));
+                } catch (ParseException e) {
+                    throw new IllegalArgumentException("Invalid date type:" + text, e);
+                }
+            } else {
+                context.append(text);
+            }
+        } else {
+            context.append(value);
+        }
+    }
+
+    @Override
+    public void doStartGroup(Filter.Group group, StringBuilder context) {
+        context.append("(");
+    }
+
+    @Override
+    public void doEndGroup(Filter.Group group, StringBuilder context) {
+        context.append(")");
+    }
+
+}