diff --git a/api-service/pom.xml b/api-service/pom.xml
index 67ed083..a6777b8 100644
--- a/api-service/pom.xml
+++ b/api-service/pom.xml
@@ -43,6 +43,11 @@
             <artifactId>mysql-connector-java</artifactId>
             <version>8.0.29</version>
         </dependency>
+        <dependency>
+            <groupId>com.github.l42111996</groupId>
+            <artifactId>kcp-base</artifactId>
+            <version>1.6</version>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/ApiServiceApplication.java b/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/ApiServiceApplication.java
index 3af7c04..790bfa6 100644
--- a/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/ApiServiceApplication.java
+++ b/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/ApiServiceApplication.java
@@ -1,6 +1,7 @@
 package cn.edu.zjvtit.cloudstorage.apiservice;
 
 import cn.edu.zjvtit.cloudstorage.apiservice.store.DataServerStore;
+import com.backblaze.erasure.ReedSolomon;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.boot.SpringApplication;
@@ -23,7 +24,21 @@ public class ApiServiceApplication extends SpringBootServletInitializer {
     private static final Logger logger = LoggerFactory.getLogger(ApiServiceApplication.class);
 
     public static void main(String[] args) {
-        SpringApplication.run(ApiServiceApplication.class, args);
+        ReedSolomon codec = ReedSolomon.create(4,2);
+        byte[][] shards = new byte[6][];
+        shards[0] = new byte[]{0, 1};
+        shards[1] = new byte[]{4, 5};
+        shards[2] = new byte[2]; //2,3
+        shards[3] = new byte[2]; //6,7
+        shards[4] = new byte[]{44,45};
+        shards[5] = new byte[]{40,41};
+        boolean[] shardPresent = new boolean[]{true,true,false,false,true,true};
+        codec.decodeMissing(shards,shardPresent,0,2);
+        for(byte[] shard:shards){
+            System.out.println(shard[0]);
+            System.out.println(shard[1]);
+        }
+
     }
 
     @Bean
diff --git a/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/controller/ObjectsController.java b/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/controller/ObjectsController.java
index d4a1faa..e3ef498 100644
--- a/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/controller/ObjectsController.java
+++ b/api-service/src/main/java/cn/edu/zjvtit/cloudstorage/apiservice/controller/ObjectsController.java
@@ -5,6 +5,9 @@ import cn.edu.zjvtit.cloudstorage.apiservice.entity.ObjectEntity;
 import cn.edu.zjvtit.cloudstorage.apiservice.rabbitmq.topic.Sender;
 import cn.edu.zjvtit.cloudstorage.apiservice.repository.ObjectRepository;
 import cn.edu.zjvtit.cloudstorage.apiservice.store.DataServerStore;
+import com.backblaze.erasure.ByteInputOutputExpCodingLoop;
+import com.backblaze.erasure.CodingLoop;
+import com.backblaze.erasure.ReedSolomon;
 import com.rabbitmq.client.Channel;
 import org.slf4j.Logger;
 import org.springframework.amqp.core.BindingBuilder;
@@ -36,6 +39,8 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.logging.Level;
 
+import static java.util.Arrays.copyOfRange;
+
 @RestController
 public class ObjectsController {
     @Autowired
@@ -63,13 +68,7 @@ public class ObjectsController {
         }
         String md5 = headers.get("md5");
         ObjectEntity object = this.objectRepository.findFirstByNameOrderByVersionDesc(filename);
-        if (object == null) {
-            object = new ObjectEntity();
-            object.setName(filename);
-            object.setHash(md5);
-            object.setVersion(1);
-            object.setSize(requestBody.length);
-        } else {
+        if (object != null) {
             if (md5.equals(object.getHash())) {
                 return new Result("object already exists", "10001").toString();
             }
@@ -79,25 +78,48 @@ public class ObjectsController {
             object.setHash(md5);
             object.setVersion(version);
             object.setSize(requestBody.length);
+        } else {
+            object = new ObjectEntity();
+            object.setName(filename);
+            object.setHash(md5);
+            object.setVersion(1);
+            object.setSize(requestBody.length);
         }
+
+        int blockSize = (int) Math.ceil(requestBody.length / 4.0);
+        ReedSolomon codec = ReedSolomon.create(4, 2);
+        byte[][] shards = new byte[6][];
+        shards[0] = copyOfRange(requestBody, 0, blockSize - 1);
+        shards[1] = copyOfRange(requestBody, blockSize, 2 * blockSize - 1);
+        shards[2] = copyOfRange(requestBody, 2 * blockSize, 3 * blockSize - 1);
+        shards[3] = new byte[blockSize];
+        for (int i = 3 * blockSize; i < requestBody.length - 1; i++) {
+            shards[3][i - 3 * blockSize] = requestBody[i];
+        }
+        shards[4] = new byte[blockSize];
+        shards[5] = new byte[blockSize];
+        codec.encodeParity(shards, 0,blockSize);
+        // todo storage shards
+
         this.objectRepository.save(object);
-        String apiUrl = "http://"+server;
-        MultiValueMap<String, String> haderWithMd5 = new HttpHeaders();;
+        String apiUrl = "http://" + server;
+        MultiValueMap<String, String> haderWithMd5 = new HttpHeaders();
+        ;
         haderWithMd5.add("md5", md5);
         // 获取uuid
         ResponseEntity<Result> ret = this.restTemplate.exchange(apiUrl + "/temp", HttpMethod.POST, new HttpEntity<>(null, haderWithMd5), Result.class);
         String uuid = (String) Objects.requireNonNull(ret.getBody()).getData().get("uuid");
         // 发送patch请求上传文件
         HttpEntity<byte[]> request = new HttpEntity<>(requestBody);
-        ret = this.restTemplate.exchange(apiUrl+"/temp/"+uuid, HttpMethod.PATCH, request, Result.class);
+        ret = this.restTemplate.exchange(apiUrl + "/temp/" + uuid, HttpMethod.PATCH, request, Result.class);
         String retMd5 = (String) Objects.requireNonNull(ret.getBody()).getData().get("md5");
-        if (Objects.equals(md5, retMd5)){
+        if (Objects.equals(md5, retMd5)) {
             // 将临时文件转为正式文件
-            this.restTemplate.exchange(apiUrl+"/temp/"+uuid, HttpMethod.PUT, new HttpEntity<>(null, haderWithMd5), Result.class);
+            this.restTemplate.exchange(apiUrl + "/temp/" + uuid, HttpMethod.PUT, new HttpEntity<>(null, haderWithMd5), Result.class);
             return new Result("success", "10000").toString();
         } else {
             // 删除文件
-            this.restTemplate.exchange(apiUrl+"/temp/"+uuid, HttpMethod.DELETE, new HttpEntity<>(null, haderWithMd5), Result.class);
+            this.restTemplate.exchange(apiUrl + "/temp/" + uuid, HttpMethod.DELETE, new HttpEntity<>(null, haderWithMd5), Result.class);
             return new Result("md5 not match", "10002").toString();
         }
 
diff --git a/pom.xml b/pom.xml
index 4db5808..5baacfc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,27 +21,14 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-amqp</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
-        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-data-mongodb</artifactId>
-        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.springframework.kafka</groupId>
-            <artifactId>spring-kafka</artifactId>
-        </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-devtools</artifactId>
@@ -63,11 +50,6 @@
             <artifactId>spring-rabbit-test</artifactId>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.springframework.kafka</groupId>
-            <artifactId>spring-kafka-test</artifactId>
-            <scope>test</scope>
-        </dependency>
     </dependencies>
 
     <build>