diff --git a/src/main/java/minsecurity/identity/persist/Persist.java b/src/main/java/minsecurity/identity/persist/Persist.java
index c0eea37..44fac82 100644
--- a/src/main/java/minsecurity/identity/persist/Persist.java
+++ b/src/main/java/minsecurity/identity/persist/Persist.java
@@ -5,6 +5,7 @@ import minsecurity.identity.Identity;
 import minsecurity.identity.persist.sqlite.Sqlite;
 import minsecurity.identity.persist.sqlite.db.Db;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class Persist {
@@ -16,6 +17,8 @@ public class Persist {
      * @throws Exception
      */
     public static void persistIdentity(Identity identity) throws Exception{
+        if (identity == null)
+            throw new Exception("Identity is null");
         switch (persistPlugin){
             case Common.SQLITE:
                 Db.persistIdentity(identity);
@@ -28,6 +31,8 @@ public class Persist {
      * @throws Exception
      */
     public static void deleteIdentityByNameFromStorage(String name) throws Exception{
+        if (name == null || name.length() == 0)
+            throw new Exception("name is empty");
         switch (persistPlugin){
             case Common.SQLITE:
                 Db.deleteIdentityByName(name);
@@ -42,6 +47,9 @@ public class Persist {
      * @throws Exception
      */
     public static Identity getIdentityByNameFromStorage(String name, String passwd) throws Exception{
+        if (name == null || name.length() == 0)
+            return null;
+
         switch (persistPlugin){
             case Common.SQLITE:
                 return Db.getIdentityByNameFromStorage(name);
@@ -60,7 +68,7 @@ public class Persist {
             case Common.SQLITE:
                 return Db.getAllIdentityFromStorage();
         }
-        return null;
+        return new ArrayList<Identity>();
     }
 
     /**
@@ -69,6 +77,9 @@ public class Persist {
      * @throws Exception
      */
     public static void setDefaultIdentityByNameInStorage(String name) throws Exception{
+        if (name == null || name.length() == 0)
+            throw new Exception("name is empty");
+
         switch (persistPlugin){
             case Common.SQLITE:
                 Db.SetDefaultIdentityByNameInStorage(name);
@@ -78,7 +89,7 @@ public class Persist {
     /**
      * 获得当前系统默认使用的Identity对象
      * @param passwd
-     * @return
+     * @return Identity
      * @throws Exception
      */
     public static Identity getDefaultIdentityFromStorage(String passwd) throws Exception{
diff --git a/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java b/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java
index 8f8ff8f..a9426a4 100644
--- a/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java
+++ b/src/main/java/minsecurity/identity/persist/sqlite/Sqlite.java
@@ -36,12 +36,16 @@ public class Sqlite {
 
     }
 
+    /**
+     * 将密码转换为16进制表示
+     * @return 16进制字符串 String
+     */
     private String passwd2HexKey(){
         return String.format("x'%s'", passwd);
     }
 
     /**
-     * 获取Sqlite object
+     * 获取Sqlite 实例
      * @return Sqlite object
      */
     public static Sqlite getInstance() {
@@ -90,10 +94,19 @@ public class Sqlite {
         }
     }
     //自定义文件地址,注意要用/结尾,比如:/min/identity/
+
+    /**
+     * 打开用户指定路径的数据库文件
+     * @param filePath String
+     * @throws Exception
+     */
     public void open(String filePath) throws Exception {
         Connection c = null;
         Statement stmt = null;
         try{
+            if (filePath == null || filePath.length() == 0){
+                throw new Exception("invalid db path!");
+            }
             db_path = filePath;
             boolean db_exists = SqliteUtil.pathExists(db_path);
             if (!db_exists){
@@ -114,6 +127,11 @@ public class Sqlite {
         }
     }
 
+    /**
+     * 从打开的数据库获取连接
+     * @return Connection
+     * @throws Exception
+     */
     public Connection getConn() throws Exception {
         Connection c = null;
         try{
diff --git a/src/main/java/minsecurity/identity/persist/sqlite/SqliteUtil.java b/src/main/java/minsecurity/identity/persist/sqlite/SqliteUtil.java
index 03820c8..d62cedf 100644
--- a/src/main/java/minsecurity/identity/persist/sqlite/SqliteUtil.java
+++ b/src/main/java/minsecurity/identity/persist/sqlite/SqliteUtil.java
@@ -24,9 +24,11 @@ public final class SqliteUtil {
     /**
      * 判断文件是否存在
      * @param path 特定文件路径
-     * @return 判断结果
+     * @return 判断结果 boolean
      */
     public static boolean pathExists(String path){
+        if (path == null)
+            return false;
         File file = new File(path);
         return file.exists();
     }
diff --git a/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java b/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java
index 070799f..cfdee2a 100644
--- a/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java
+++ b/src/main/java/minsecurity/identity/persist/sqlite/db/Db.java
@@ -214,7 +214,7 @@ public final class Db {
 
     public static void deleteIdentityByName(String name) throws Exception{
         Connection c = Sqlite.getInstance().getConn();
-        PreparedStatement pstmt = c.prepareStatement("elete from identityinfo where name=?");
+        PreparedStatement pstmt = c.prepareStatement("delete from identityinfo where name=?");
         pstmt.setString(1, name);
         pstmt.executeUpdate();
         pstmt.close();
diff --git a/src/test/java/minsecurity/identity/TestPersist.java b/src/test/java/minsecurity/identity/TestPersist.java
index 5c41cdc..13a16a8 100644
--- a/src/test/java/minsecurity/identity/TestPersist.java
+++ b/src/test/java/minsecurity/identity/TestPersist.java
@@ -5,10 +5,13 @@ import minsecurity.Common;
 import minsecurity.certificate.cert.CertUtils;
 import minsecurity.certificate.cert.Certificate;
 import minsecurity.crypto.sm2.SM2Base;
+import minsecurity.crypto.sm2.SM2KeyPair;
 import minsecurity.crypto.sm2.SM2PrivateKey;
 import minsecurity.crypto.sm2.SM2PublicKey;
 import minsecurity.identity.persist.IdentitySerializer;
 import minsecurity.identity.persist.MapDB;
+import minsecurity.identity.persist.Persist;
+import minsecurity.identity.persist.sqlite.Sqlite;
 import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
 import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
@@ -17,6 +20,7 @@ import org.mapdb.BTreeMap;
 import org.mapdb.DB;
 import org.mapdb.DBMaker;
 import org.mapdb.Serializer;
+import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.*;
@@ -32,136 +36,185 @@ import java.util.concurrent.ConcurrentMap;
 public class TestPersist {
     private static final org.slf4j.Logger logger = LoggerFactory.getLogger(TestIdentity.class);
 
-    @Test
-    public void testMapDB() throws Exception {
+    /**
+     * 随机生成身份数据
+     * @return Identity
+     */
+    private Identity createRandomIdentity() throws Exception{
+        // 测试PersistIdentity
+        SM2KeyPair pair = SM2KeyPair.generateKeyPair();
+        Identity identity = new Identity();
+        identity.setName("wzq"+Math.random());
+        KeyParam keyParam = new KeyParam();
+        keyParam.PublicKeyAlgorithm = 0;
+        keyParam.SignatureAlgorithm = 0;
+        identity.setKeyParam(keyParam);
+        identity.setPrikey(pair.getSm2PrivateKey());
+        identity.setPubkey(pair.getSm2PublicKey());
+        identity.setPasswd("2DD29CA851E7B56E4697B0E1F08507293D761A05CE4D1B628663F411A8086D99");
+        identity.lock("0123456789abcdef", Common.SM4ECB);
+        Certificate cert = new Certificate();
+        cert.setVersion(1);
+        cert.setSerialNumber(1);
+        cert.setPublicKey(pair.getSm2PublicKey());
+        cert.setSignatureAlgorithm(Common.SM3withSM2); // TODO 名字有误？ SM2withSM3?
+        cert.setPublicKeyAlgorithm(Common.SM2);
+        cert.setIssueTo("root");
+        cert.setIssuer("root");
+        long timestamp = System.currentTimeMillis() / 1000;
+        cert.setTimestamp(timestamp); // 10bit timestamp
+        cert.setNotAfter(timestamp); // 10bit timestamp
+        cert.setNotBefore(timestamp + 1000); // 10bit timestamp
+        cert.setKeyUsage(Common.CertSign);
+        cert.setCA(true);
+        CertUtils.signCert(cert, pair.getSm2PrivateKey());
 
-        AsymmetricCipherKeyPair keyPair = SM2Base.generateKeyPairParameter();
-        ECPrivateKeyParameters priKey = (ECPrivateKeyParameters) keyPair.getPrivate();
-        ECPublicKeyParameters pubKey = (ECPublicKeyParameters) keyPair.getPublic();
-        byte[] d = priKey.getD().toByteArray();
-        // d = Arrays.copyOf(d,32);
-        byte[] x = pubKey.getQ().getAffineXCoord().getEncoded();
-        byte[] y = pubKey.getQ().getAffineYCoord().getEncoded();
-        // BigInteger bigInteger = priKey.getD();
-        SM2PrivateKey sm2PrivateKey = new SM2PrivateKey(d);
-        SM2PublicKey sm2PublicKey = new SM2PublicKey(x,y);
-        KeyParam keyParam = new KeyParam(Common.SM2, Common.SM3withSM2);
-        Identity identity = new Identity("root",keyParam,sm2PrivateKey,sm2PublicKey, "123456", null, false);
-        Certificate certificate = new Certificate(1, 1, sm2PublicKey, null,
-                Common.SM3withSM2, Common.SM2, "root", "root",
-                System.currentTimeMillis() - 1000, System.currentTimeMillis() + 5000,
-                Common.CertSign, true, System.currentTimeMillis());
-        CertUtils.signCert(certificate, sm2PrivateKey);
-        identity.setCert(certificate);
-        MapDB mapDB = MapDB.getInstance("./target/test.db");
-        int random = new Random().nextInt();
-        mapDB.addIdentity("/test" + random, identity, false);
-        mapDB.commit();
-        mapDB.closeDB();
-        mapDB = MapDB.getInstance("./target/test.db");
-        ArrayList<Identity> arrayList = mapDB.getAllIdentity();
-        logger.debug("db size: {}",arrayList.size());
-        Identity id = mapDB.getIdentityByName("/test" + random);
-        logger.debug(identity.toString());
-        logger.debug(id.toString());
-    }
-
-    @Test
-    public void testMapDB2() throws Exception {
-        MapDB mapDB = MapDB.getInstance("./target/test.db");
-        for(int i = 0; i < 100; i++){
-            AsymmetricCipherKeyPair keyPair = SM2Base.generateKeyPairParameter();
-            ECPrivateKeyParameters priKey = (ECPrivateKeyParameters) keyPair.getPrivate();
-            ECPublicKeyParameters pubKey = (ECPublicKeyParameters) keyPair.getPublic();
-            byte[] d = priKey.getD().toByteArray();
-            // d = Arrays.copyOf(d,32);
-            byte[] x = pubKey.getQ().getAffineXCoord().getEncoded();
-            byte[] y = pubKey.getQ().getAffineYCoord().getEncoded();
-            // BigInteger bigInteger = priKey.getD();
-            SM2PrivateKey sm2PrivateKey = new SM2PrivateKey(d);
-            SM2PublicKey sm2PublicKey = new SM2PublicKey(x,y);
-            KeyParam keyParam = new KeyParam(Common.SM2, Common.SM3withSM2);
-            Identity identity = new Identity("root",keyParam,sm2PrivateKey,sm2PublicKey, "123456", null, false);
-            Certificate certificate = new Certificate(1, 1, sm2PublicKey, null,
-                    Common.SM3withSM2, Common.SM2, "root", "root",
-                    System.currentTimeMillis() - 1000, System.currentTimeMillis() + 5000,
-                    Common.CertSign, true, System.currentTimeMillis());
-            CertUtils.signCert(certificate, sm2PrivateKey);
-            identity.setCert(certificate);
-            int random = new Random().nextInt();
-            mapDB.addIdentity("/test" + random, identity, false);
-        }
-        mapDB.commit();
-        ArrayList<Identity> arrayList = mapDB.getAllIdentity();
-        logger.debug("size = {}", arrayList.size());
-        for(Identity id : arrayList){
-            logger.debug(id.toString());
-        }
-    }
-
-    @Test
-    public void testHashmap(){
-        HashMap<String, Integer> primeNumbers = new HashMap<>();
-
-        // 往HasMap中添加映射
-        primeNumbers.put("Two", 2);
-        primeNumbers.put("Three", 3);
-        primeNumbers.put("Five", 5);
-        System.out.println("HashMap: " + primeNumbers);
-
-        // 得到value
-        Integer value = primeNumbers.get("Three");
-        System.out.println("key Three 对应的 value: " + value);
-
-    }
-
-    @Test
-    public void testDefault() throws Exception {
-        MapDB mapDB = MapDB.getInstance("./target/test.db");
-        for(int i = 0; i < 20; i++){
-            int random = new Random().nextInt();
-            Identity identity = generateIdentity("/test/" + random);
-            mapDB.addIdentity(identity.getName(), identity, false);
-        }
-        // mapDB.commit();
-        ArrayList<Identity> arrayList = mapDB.getAllIdentity();
-        logger.debug("size = {}", arrayList.size());
-        for(Identity id : arrayList){
-            logger.debug(id.getName() + " " + id.isDefault());
-        }
-        logger.debug("----setDefault----");
-        Identity identity = generateIdentity("/abc");
-        identity.setDefault(true);
-        mapDB.addIdentity("/abc", identity, false);
-        mapDB.setDefaultIdentity("/abc",false);
-        mapDB.commit();
-
-        arrayList = mapDB.getAllIdentity();
-        for(Identity id : arrayList){
-            logger.debug(id.getName() + " " + id.isDefault());
-        }
-        logger.debug("get default");
-        logger.debug(mapDB.getDefaultIdentity().toString());
-    }
-
-
-    private Identity generateIdentity(String name) throws Exception {
-        AsymmetricCipherKeyPair keyPair = SM2Base.generateKeyPairParameter();
-        ECPrivateKeyParameters priKey = (ECPrivateKeyParameters) keyPair.getPrivate();
-        ECPublicKeyParameters pubKey = (ECPublicKeyParameters) keyPair.getPublic();
-        byte[] d = priKey.getD().toByteArray();
-        byte[] x = pubKey.getQ().getAffineXCoord().getEncoded();
-        byte[] y = pubKey.getQ().getAffineYCoord().getEncoded();
-        SM2PrivateKey sm2PrivateKey = new SM2PrivateKey(d);
-        SM2PublicKey sm2PublicKey = new SM2PublicKey(x,y);
-        KeyParam keyParam = new KeyParam(Common.SM2, Common.SM3withSM2);
-        Identity identity = new Identity(name,keyParam,sm2PrivateKey,sm2PublicKey, "123456", null, false);
-        Certificate certificate = new Certificate(1, 1, sm2PublicKey, null,
-                Common.SM3withSM2, Common.SM2, "root", "root",
-                System.currentTimeMillis() - 1000, System.currentTimeMillis() + 5000,
-                Common.CertSign, true, System.currentTimeMillis());
-        CertUtils.signCert(certificate, sm2PrivateKey);
-        identity.setCert(certificate);
+        identity.setCert(cert);
         return identity;
     }
+
+    /**
+     * 测试PersistIdentity正常使用
+     */
+    @Test
+    public void testPersistIdentity(){
+        try{
+            // 打开数据库
+            Sqlite.getInstance().openDefault();
+            // 重复五次随机生成并插入数据库过程
+            for (int i = 0; i < 5; i++) {
+                Identity id = createRandomIdentity();
+                Persist.persistIdentity(id);
+            }
+
+            // 获取数据库中所有数据
+            List<Identity> identities = Persist.getAllIdentityFromStorage("");
+            for (Identity i:
+                 identities) {
+                logger.debug("当前用户："+i.getName());
+                // 测试 getIdentityByNameFromStorage
+                Identity id = Persist.getIdentityByNameFromStorage(i.getName(), "");
+                logger.debug("查询用户："+id.getName());
+            }
+        }catch (Exception ex){
+            logger.debug(String.format("测试失败:%s", ex.getMessage()));
+        }
+    }
+
+    /**
+     * 测试PersistIdentity异常使用
+     */
+    @Test
+    public void testPersistIdentity2(){
+        try{
+            // 打开数据库
+            Sqlite.getInstance().openDefault();
+            // 重复五次null插入数据库过程
+            for (int i = 0; i < 5; i++) {
+                Persist.persistIdentity(null); // 抛异常
+            }
+
+            // 获取数据库中所有数据
+            List<Identity> identities = Persist.getAllIdentityFromStorage("");
+            for (Identity i:
+                    identities) {
+                logger.debug(i.getName());
+                Identity id = Persist.getIdentityByNameFromStorage(i.getName(), "");
+                logger.debug("查询用户："+id.getName());
+            }
+        }catch (Exception ex){
+            logger.debug(String.format("测试失败:%s", ex.getMessage()));
+        }
+    }
+
+    /**
+     * 测试SetDefaultIdentity正常使用
+     */
+    @Test
+    public void testSetDefaultIdentity(){
+        try{
+            // 打开数据库
+            Sqlite.getInstance().openDefault();
+
+            // 获取数据库中所有数据，并轮流设置默认身份
+            List<Identity> identities = Persist.getAllIdentityFromStorage("");
+            for (Identity i:
+                    identities) {
+                logger.debug(String.format("为 %s 设置默认身份", i.getName()));
+                Persist.setDefaultIdentityByNameInStorage(i.getName());
+                Identity did = Persist.getDefaultIdentityFromStorage("");
+                logger.debug(String.format("当前默认身份 %s", did.getName()));
+            }
+        }catch (Exception ex){
+            logger.debug(String.format("测试失败:%s", ex.getMessage()));
+        }
+    }
+
+    /**
+     * 测试SetDefaultIdentity异常使用
+     */
+    @Test
+    public void testSetDefaultIdentity2(){
+        try{
+            // 打开数据库
+            Sqlite.getInstance().openDefault();
+
+            // 故意设置错误默认身份
+            List<Identity> identities = Persist.getAllIdentityFromStorage("");
+            for (Identity i:
+                    identities) {
+                logger.debug(String.format("为 %s 设置默认身份", i.getName()));
+                Persist.setDefaultIdentityByNameInStorage(null);
+                Persist.setDefaultIdentityByNameInStorage("");
+                Identity did = Persist.getDefaultIdentityFromStorage("");
+                logger.debug(String.format("当前默认身份 %s", did.getName()));
+            }
+        }catch (Exception ex){
+            logger.debug(String.format("测试失败:%s", ex.getMessage()));
+        }
+    }
+
+    /**
+     * 测试DeleteIdentityByName正常使用
+     */
+    @Test
+    public void testDeleteIdentityByName(){
+        try{
+            // 打开数据库
+            Sqlite.getInstance().openDefault();
+
+            // 根据用户name先删除再查询
+            List<Identity> identities = Persist.getAllIdentityFromStorage("");
+            for (Identity i:
+                    identities) {
+                logger.debug(String.format("删除名称为 %s 的用户", i.getName()));
+                Persist.deleteIdentityByNameFromStorage(i.getName());
+                Identity did = Persist.getIdentityByNameFromStorage(i.getName(), "");
+                logger.debug(String.format("查询 %s 结果: %s", i.getName(), did));
+            }
+        }catch (Exception ex){
+            logger.debug(String.format("测试失败:%s", ex.getMessage()));
+        }
+    }
+
+    /**
+     * 测试DeleteIdentityByName异常使用
+     */
+    @Test
+    public void testDeleteIdentityByName2(){
+        try{
+            // 打开数据库
+            Sqlite.getInstance().openDefault();
+
+            // 故意删除错误身份
+            List<Identity> identities = Persist.getAllIdentityFromStorage("");
+            for (Identity i:
+                    identities) {
+                logger.debug(String.format("删除名称为 %s 的用户", null));
+                Persist.deleteIdentityByNameFromStorage(null);
+            }
+        }catch (Exception ex){
+            logger.debug(String.format("测试失败:%s", ex.getMessage()));
+        }
+    }
 }
diff --git a/src/test/java/minsecurity/identity/sqlite/SqliteTest.java b/src/test/java/minsecurity/identity/sqlite/SqliteTest.java
index 2aca043..bfef279 100644
--- a/src/test/java/minsecurity/identity/sqlite/SqliteTest.java
+++ b/src/test/java/minsecurity/identity/sqlite/SqliteTest.java
@@ -13,6 +13,9 @@ public class SqliteTest {
         assertFalse(SqliteUtil.pathExists("/aaa/1.txt"));
     }
 
+    /**
+     * 正常情况连接数据库测试
+     */
     @Test
     public void TestSqliteOpen(){
         try{
@@ -35,12 +38,32 @@ public class SqliteTest {
         }
     }
 
+    /**
+     * 输入异常数据测试连接数据库
+     */
+    @Test
+    public void TestSqliteOpen2(){
+        try{
+            // Sqlite.getInstance().open(""); 报异常
+            Sqlite.getInstance().open(null); // 报异常
+            boolean res1 = SqliteUtil.pathExists("/home/zhengqi/test/identity.db");
+            if (!res1){
+                throw new Exception("no target db file!!");
+            }
+        }catch (Exception ex){
+            System.out.println(ex.getMessage());
+        }
+    }
+
+    /**
+     * 测试修改密码后连接数据库
+     */
     @Test
     public void TestSqliteSetPasswd(){
         try{
             String newPasswd = "1DD29CA851E7B56E4697B0E1F08507293D761A05CE4D1B628663F411A8086D99";
             Sqlite.getInstance().setPasswd(newPasswd);
-            Sqlite.getInstance().open("/home/zhengqi/min/identity/");
+            Sqlite.getInstance().open("/home/zhengqi/min/identity/"); // 报异常 数据库密码错误
             // Sqlite.getInstance().getConn();
         }catch (Exception ex){
             System.out.println(ex.getMessage());