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diff --git a/src/main/.DS_Store b/src/main/.DS_Store
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diff --git a/src/main/java/.DS_Store b/src/main/java/.DS_Store
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diff --git a/src/main/java/edu/.DS_Store b/src/main/java/edu/.DS_Store
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diff --git a/src/main/java/edu/tcu/.DS_Store b/src/main/java/edu/tcu/.DS_Store
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diff --git a/src/main/java/edu/tcu/cs/.DS_Store b/src/main/java/edu/tcu/cs/.DS_Store
new file mode 100644
index 0000000..c899317
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diff --git a/src/main/java/edu/tcu/cs/expensetracker/.DS_Store b/src/main/java/edu/tcu/cs/expensetracker/.DS_Store
new file mode 100644
index 0000000..5d62efc
Binary files /dev/null and b/src/main/java/edu/tcu/cs/expensetracker/.DS_Store differ
diff --git a/src/main/java/edu/tcu/cs/expensetracker/ExpensetrackerApplication.java b/src/main/java/edu/tcu/cs/expensetracker/ExpensetrackerApplication.java
index 7faa64b..1de2bfb 100644
--- a/src/main/java/edu/tcu/cs/expensetracker/ExpensetrackerApplication.java
+++ b/src/main/java/edu/tcu/cs/expensetracker/ExpensetrackerApplication.java
@@ -6,8 +6,8 @@
 @SpringBootApplication
 public class ExpensetrackerApplication {
 
-    public static void main(String[] args) {
-        SpringApplication.run(ExpensetrackerApplication.class, args);
-    }
+	public static void main(String[] args) {
+		SpringApplication.run(ExpensetrackerApplication.class, args);
+	}
 
-}
+}
\ No newline at end of file
diff --git a/src/main/java/edu/tcu/cs/expensetracker/controller/ExpenseController.java b/src/main/java/edu/tcu/cs/expensetracker/controller/ExpenseController.java
new file mode 100644
index 0000000..55a167e
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/controller/ExpenseController.java
@@ -0,0 +1,57 @@
+package edu.tcu.cs.expensetracker.controller;
+
+import edu.tcu.cs.expensetracker.domain.Expense;
+import edu.tcu.cs.expensetracker.domain.Result;
+import edu.tcu.cs.expensetracker.domain.StatusCode;
+import edu.tcu.cs.expensetracker.service.ExpenseService;
+
+import org.springframework.web.bind.annotation.*;
+
+import java.time.LocalDate;
+import java.util.List;
+
+@RestController
+@RequestMapping("/expenses")
+public class ExpenseController {
+
+    private ExpenseService expenseService;
+
+    public ExpenseController(ExpenseService expenseService) {
+        this.expenseService = expenseService;
+    }
+
+    @GetMapping
+    public Result findAll(){
+        List<Expense> all = expenseService.findAll();
+        Result result = new Result(true, StatusCode.SUCCESS, "Find All Success", all);
+        return result;
+    }
+    @GetMapping("/{expenseId}")
+    public Result findById(@PathVariable String expenseId) {
+        return new Result(true, StatusCode.SUCCESS, "Find One Success", expenseService.findById(expenseId));
+    }
+
+    @GetMapping("/{expenseStart}/{expenseEnd}")
+    public Result findById(@PathVariable String expenseStart, @PathVariable String expenseEnd) {
+        LocalDate expenseStartDate = LocalDate.parse(expenseStart);
+        LocalDate expenseEndDate = LocalDate.parse(expenseEnd);
+        return new Result(true, StatusCode.SUCCESS, "Find Between Dates Success", expenseService.findBetweenDates(expenseStartDate, expenseEndDate));
+    }
+
+    @PostMapping
+    public Result save(@RequestBody Expense newExpense){
+        expenseService.save(newExpense);
+        return new Result(true, StatusCode.SUCCESS, "Save Success");
+    }
+    @PutMapping("/{expenseId}")
+    public Result update(@PathVariable String expenseId, @RequestBody Expense updatedExpense) {
+        expenseService.update(expenseId, updatedExpense);
+        return new Result(true, StatusCode.SUCCESS, "Update Success");
+    }
+    @DeleteMapping("/{expenseId}")
+    public Result delete(@PathVariable String expenseId){
+        expenseService.delete(expenseId);
+        return new Result(true, StatusCode.SUCCESS, "Delete Success");
+
+    }
+}
diff --git a/src/main/java/edu/tcu/cs/expensetracker/dao/ExpenseDao.java b/src/main/java/edu/tcu/cs/expensetracker/dao/ExpenseDao.java
new file mode 100644
index 0000000..814ec8f
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/dao/ExpenseDao.java
@@ -0,0 +1,7 @@
+package edu.tcu.cs.expensetracker.dao;
+
+import edu.tcu.cs.expensetracker.domain.Expense;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ExpenseDao extends JpaRepository<Expense, String> {
+}
diff --git a/src/main/java/edu/tcu/cs/expensetracker/datainitializer/ExpenseDataInitializer.java b/src/main/java/edu/tcu/cs/expensetracker/datainitializer/ExpenseDataInitializer.java
new file mode 100644
index 0000000..66ebd4f
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/datainitializer/ExpenseDataInitializer.java
@@ -0,0 +1,147 @@
+package edu.tcu.cs.expensetracker.datainitializer;
+
+import edu.tcu.cs.expensetracker.dao.ExpenseDao;
+import edu.tcu.cs.expensetracker.domain.Expense;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.stereotype.Component;
+
+@Component
+public class ExpenseDataInitializer implements CommandLineRunner {
+
+    private ExpenseDao expenseDao;
+
+    public ExpenseDataInitializer(ExpenseDao expenseDao) {
+        this.expenseDao = expenseDao;
+    }
+
+    @Override
+    public void run(String... args) throws Exception {
+        Expense e1 = new Expense();
+        e1.setId("1");
+        e1.setName("Dining Spending");
+        e1.setMoney("247");
+        e1.setAccount("Chase Bank");
+        e1.setCreateTime("2016-03-02");
+        e1.setDescription("Dutch Burger");
+
+        Expense e2 = new Expense();
+        e2.setId("2");
+        e2.setName("Salary Income");
+        e2.setMoney("3000");
+        e2.setAccount("Cash");
+        e2.setCreateTime("2016-03-15");
+        e2.setDescription("September Salary");
+
+        Expense e3 = new Expense();
+        e3.setId("3");
+        e3.setName("Books Spending");
+        e3.setMoney("200");
+        e3.setAccount("Cash");
+        e3.setCreateTime("2016-04-02");
+        e3.setDescription("Calculus Book");
+
+        Expense e4 = new Expense();
+        e4.setId("4");
+        e4.setName("Dining Spending");
+        e4.setMoney("325");
+        e4.setAccount("Cash");
+        e4.setCreateTime("2016-06-18");
+        e4.setDescription("Eat at TCU Cafe");
+
+        Expense e5 = new Expense();
+        e5.setId("5");
+        e5.setName("Stock Income");
+        e5.setMoney("8000");
+        e5.setAccount("WellsFargo Saving Account");
+        e5.setCreateTime("2016-10-28");
+        e5.setDescription("Apple Stock is great!");
+
+        Expense e6 = new Expense();
+        e6.setId("6");
+        e6.setName("Stock Income");
+        e6.setMoney("5000");
+        e6.setAccount("WellsFargo Saving Account");
+        e6.setCreateTime("2016-10-28");
+        e6.setDescription("Oracle Stock is great!");
+
+        Expense e7 = new Expense();
+        e7.setId("7");
+        e7.setName("Stock Income");
+        e7.setMoney("3000");
+        e7.setAccount("ChaseBank Saving Account");
+        e7.setCreateTime("2016-10-28");
+        e7.setDescription("Oct Salary time!");
+
+        Expense e8 = new Expense();
+        e8.setId("8");
+        e8.setName("Clothes Spending");
+        e8.setMoney("5000");
+        e8.setAccount("Cash");
+        e8.setCreateTime("2016-10-28");
+        e8.setDescription("JCrew again");
+
+        Expense e9 = new Expense();
+        e9.setId("9");
+        e9.setName("Other Spending");
+        e9.setMoney("20");
+        e9.setAccount("Cash");
+        e9.setCreateTime("2016-10-29");
+        e9.setDescription("Lost 20 bucks in library. :(");
+
+        Expense e10 = new Expense();
+        e10.setId("10");
+        e10.setName("Gas Spending");
+        e10.setMoney("1200");
+        e10.setAccount("ChaseBank Credit Card");
+        e10.setCreateTime("2016-10-29");
+        e10.setDescription("Gas is so expensive");
+
+        Expense e11 = new Expense();
+        e11.setId("11");
+        e11.setName("Dining Spending");
+        e11.setMoney("1000");
+        e11.setAccount("ChaseBank Debit Card");
+        e11.setCreateTime("2016-10-29");
+        e11.setDescription("Eat eat eat");
+
+        Expense e12 = new Expense();
+        e12.setId("12");
+        e12.setName("Salary Income");
+        e12.setMoney("3000");
+        e12.setAccount("ChaseBank Saving Account");
+        e12.setCreateTime("2016-10-30");
+        e12.setDescription("Nov salary");
+
+        Expense e13 = new Expense();
+        e13.setId("13");
+        e13.setName("Flight Ticket Spending");
+        e13.setMoney("500");
+        e13.setAccount("ChaseBank Debit Card");
+        e13.setCreateTime("2016-10-30");
+        e13.setDescription("Fly to LA");
+
+        Expense e14 = new Expense();
+        e14.setId("14");
+        e14.setName("Salary Income");
+        e14.setMoney("3000");
+        e14.setAccount("ChaseBank Saving Account");
+        e14.setCreateTime("2016-10-30");
+        e14.setDescription("December Salary");
+
+        expenseDao.save(e1);
+        expenseDao.save(e2);
+        expenseDao.save(e3);
+        expenseDao.save(e4);
+        expenseDao.save(e5);
+        expenseDao.save(e6);
+        expenseDao.save(e7);
+        expenseDao.save(e8);
+        expenseDao.save(e9);
+        expenseDao.save(e10);
+        expenseDao.save(e11);
+        expenseDao.save(e12);
+        expenseDao.save(e13);
+        expenseDao.save(e14);
+    }
+}
diff --git a/src/main/java/edu/tcu/cs/expensetracker/domain/Expense.java b/src/main/java/edu/tcu/cs/expensetracker/domain/Expense.java
new file mode 100644
index 0000000..9313a77
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/domain/Expense.java
@@ -0,0 +1,72 @@
+package edu.tcu.cs.expensetracker.domain;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+import java.io.Serializable;
+@Entity
+public class Expense implements Serializable {
+    @Id
+    private String id;
+    private String name;
+    private String description;
+    private String money;
+    private String account;
+    private String createTime;
+    @ManyToOne
+    @JsonIgnore
+    private Expense owner;
+
+    public Expense() {
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getMoney() {
+        return money;
+    }
+
+    public void setMoney(String money) {
+        this.money = money;
+    }
+
+    public String getAccount() {
+        return account;
+    }
+
+    public void setAccount(String account) {
+        this.account = account;
+    }
+
+    public String getCreateTime() {
+        return createTime;
+    }
+
+    public void setCreateTime(String createTime) {
+        this.createTime = createTime;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+}
diff --git a/src/main/java/edu/tcu/cs/expensetracker/domain/Result.java b/src/main/java/edu/tcu/cs/expensetracker/domain/Result.java
new file mode 100644
index 0000000..0fd2992
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/domain/Result.java
@@ -0,0 +1,60 @@
+package edu.tcu.cs.expensetracker.domain;
+
+/*
+used to encapsulate data prepared by server side, this object will be serialized to JSON before
+sent back to front end
+ */
+public class Result {
+    private boolean flag; //true: success, false: not success
+    private Integer code; //return status code. e.g. 200
+    private String message; // message
+    private Object data; //return the requested data, in this case, a PageBean object
+
+    public Result() {
+    }
+
+    public Result(boolean flag, Integer code, String message) {
+        this.flag = flag;
+        this.code = code;
+        this.message = message;
+    }
+
+    public Result(boolean flag, Integer code, String message, Object data) {
+        this.flag = flag;
+        this.code = code;
+        this.message = message;
+        this.data = data;
+    }
+
+    public boolean isFlag() {
+        return flag;
+    }
+
+    public void setFlag(boolean flag) {
+        this.flag = flag;
+    }
+
+    public Integer getCode() {
+        return code;
+    }
+
+    public void setCode(Integer code) {
+        this.code = code;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+    public Object getData() {
+        return data;
+    }
+
+    public void setData(Object data) {
+        this.data = data;
+    }
+}
diff --git a/src/main/java/edu/tcu/cs/expensetracker/domain/StatusCode.java b/src/main/java/edu/tcu/cs/expensetracker/domain/StatusCode.java
new file mode 100644
index 0000000..f87ca6b
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/domain/StatusCode.java
@@ -0,0 +1,10 @@
+package edu.tcu.cs.expensetracker.domain;
+
+public class StatusCode {
+    public static final int SUCCESS = 200; //Success
+    public static final int FAILURE = 400; //Failure
+    public static final int UNAUTHORIZED = 401; //username or password incorrect
+    public static final int FORBIDDEN = 403; //insufficent rights
+    public static final int NOT_FOUND = 404; //API not found
+    public static final int INTERNAL_SERVER_ERROR = 500;//Repetitive ops
+}
diff --git a/src/main/java/edu/tcu/cs/expensetracker/service/ExpenseService.java b/src/main/java/edu/tcu/cs/expensetracker/service/ExpenseService.java
new file mode 100644
index 0000000..90b7d47
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/service/ExpenseService.java
@@ -0,0 +1,54 @@
+package edu.tcu.cs.expensetracker.service;
+
+import edu.tcu.cs.expensetracker.domain.Expense;
+import edu.tcu.cs.expensetracker.dao.ExpenseDao;
+import org.springframework.stereotype.Service;
+import javax.transaction.Transactional;
+
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Service
+@Transactional
+public class ExpenseService {
+
+    private ExpenseDao expenseDao;
+
+    // Spring will automatically inject an instance of ExpenseDao 
+
+    public ExpenseService(ExpenseDao expenseDao) {
+        this.expenseDao = expenseDao;
+    }
+
+    public List<Expense> findAll(){ return expenseDao.findAll(); }
+
+    public Expense findById(String expenseId) { return expenseDao.findById(expenseId).get(); }
+
+    public List<Expense> findBetweenDates(LocalDate startDate, LocalDate endDate) {
+        List <LocalDate> dateList = startDate.datesUntil(endDate).collect(Collectors.toList());
+        List <Expense> startDates = expenseDao.findAll();
+        List <Expense> endDates = new ArrayList<>();
+        
+        for (int i = 0; i < startDates.size(); i++) {
+            if (dateList.contains(LocalDate.parse(startDates.get(i).getCreateTime()))) {
+                endDates.add(startDates.get(i));
+            }
+        }
+        return endDates;
+    }
+
+    public void save(Expense newExpense) {
+        expenseDao.save(newExpense);
+    }
+
+    public void update(String expenseId, Expense updatedExpense) {
+        updatedExpense.setId(expenseId);
+        expenseDao.save(updatedExpense);
+    }
+
+    public void delete(String expenseId) {
+        expenseDao.deleteById(expenseId);
+    }
+}
diff --git a/src/main/java/edu/tcu/cs/expensetracker/utils/IdWorker.java b/src/main/java/edu/tcu/cs/expensetracker/utils/IdWorker.java
new file mode 100644
index 0000000..bbca243
--- /dev/null
+++ b/src/main/java/edu/tcu/cs/expensetracker/utils/IdWorker.java
@@ -0,0 +1,104 @@
+package edu.tcu.cs.expensetracker.utils;
+
+import java.lang.management.ManagementFactory;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+
+public class IdWorker {
+    private final static long twepoch = 1288834974657L;
+    private final static long workerIdBits = 5L;
+    private final static long datacenterIdBits = 5L;
+    private final static long maxWorkerId = -1L ^ (-1L << workerIdBits);
+    private final static long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
+    private final static long sequenceBits = 12L;
+    private final static long workerIdShift = sequenceBits;
+    private final static long datacenterIdShift = sequenceBits + workerIdBits;
+    private final static long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
+    private final static long sequenceMask = -1L ^ (-1L << sequenceBits);
+    private static long lastTimestamp = -1L;
+    private long sequence = 0L;
+    private final long workerId;
+    private final long datacenterId;
+
+    public IdWorker() {
+        this.datacenterId = getDatacenterId(maxDatacenterId);
+        this.workerId = getMaxWorkerId(datacenterId, maxWorkerId);
+    }
+
+    public IdWorker(long workerId, long datacenterId) {
+        if (workerId > maxWorkerId || workerId < 0) {
+            throw new IllegalArgumentException(String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
+        }
+        if (datacenterId > maxDatacenterId || datacenterId < 0) {
+            throw new IllegalArgumentException(String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
+        }
+        this.workerId = workerId;
+        this.datacenterId = datacenterId;
+    }
+
+    public synchronized long nextId() {
+        long timestamp = timeGen();
+        if (timestamp < lastTimestamp) {
+            throw new RuntimeException(String.format("Clock moved backwards.  Refusing to generate id for %d milliseconds", lastTimestamp - timestamp));
+        }
+
+        if (lastTimestamp == timestamp) {
+            sequence = (sequence + 1) & sequenceMask;
+            if (sequence == 0) {
+                timestamp = tilNextMillis(lastTimestamp);
+            }
+        } else {
+            sequence = 0L;
+        }
+        lastTimestamp = timestamp;
+        long nextId = ((timestamp - twepoch) << timestampLeftShift)
+                | (datacenterId << datacenterIdShift)
+                | (workerId << workerIdShift) | sequence;
+
+        return nextId;
+    }
+
+    private long tilNextMillis(final long lastTimestamp) {
+        long timestamp = this.timeGen();
+        while (timestamp <= lastTimestamp) {
+            timestamp = this.timeGen();
+        }
+        return timestamp;
+    }
+
+    private long timeGen() {
+        return System.currentTimeMillis();
+    }
+
+    protected static long getMaxWorkerId(long datacenterId, long maxWorkerId) {
+        StringBuffer mpid = new StringBuffer();
+        mpid.append(datacenterId);
+        String name = ManagementFactory.getRuntimeMXBean().getName();
+        if (!name.isEmpty()) {
+            /*
+             * GET jvmPid
+             */
+            mpid.append(name.split("@")[0]);
+        }
+        return (mpid.toString().hashCode() & 0xffff) % (maxWorkerId + 1);
+    }
+
+    protected static long getDatacenterId(long maxDatacenterId) {
+        long id = 0L;
+        try {
+            InetAddress ip = InetAddress.getLocalHost();
+            NetworkInterface network = NetworkInterface.getByInetAddress(ip);
+            if (network == null) {
+                id = 1L;
+            } else {
+                byte[] mac = network.getHardwareAddress();
+                id = ((0x000000FF & (long) mac[mac.length - 1])
+                        | (0x0000FF00 & (((long) mac[mac.length - 2]) << 8))) >> 6;
+                id = id % (maxDatacenterId + 1);
+            }
+        } catch (Exception e) {
+            System.out.println(" getDatacenterId: " + e.getMessage());
+        }
+        return id;
+    }
+}