hw0k/CalculatorController.java

## CalculatorController.java
package kr.hs.dgsw.calculator;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class CalculatorController {

    @Autowired
    private CalculatorService calculatorService;

    @RequestMapping("/add")
    public String add(@RequestParam String par1, @RequestParam String par2) {
        return calculatorService.add(par1, par2);
    }

    @RequestMapping("/subtract")
    public String subtract(@RequestParam String par1, @RequestParam String par2) {
        return calculatorService.subtract(par1, par2);
    }

    @RequestMapping("/multiply")
    public String multiply(@RequestParam String par1, @RequestParam String par2) {
        return calculatorService.multiply(par1, par2);
    }

    @RequestMapping("/divide")
    public String divide(@RequestParam String par1, @RequestParam String par2) {
        return calculatorService.divide(par1, par2);
    }
}

## CalculatorService.java
package kr.hs.dgsw.calculator;

public interface CalculatorService {
    String add(String par1, String par2);
    String subtract(String par1, String par2);
    String multiply(String par1, String par2);
    String divide(String par1, String par2);
}

## CalculatorServiceImpl.java
package kr.hs.dgsw.calculator;

import org.springframework.stereotype.Service;

@Service
public class CalculatorServiceImpl implements CalculatorService {
    @Override
    public String add(String par1, String par2) {
        return "계산 결과: " + (Integer.parseInt(par1) + Integer.parseInt(par2));
    }

    @Override
    public String subtract(String par1, String par2) {
        return "계산 결과: " + (Integer.parseInt(par1) - Integer.parseInt(par2));
    }

    @Override
    public String multiply(String par1, String par2) {
        return "계산 결과: " + (Integer.parseInt(par1) * Integer.parseInt(par2));
    }

    @Override
    public String divide(String par1, String par2) {
        return "계산 결과: " + (Integer.parseInt(par1) / Integer.parseInt(par2));
    }
}

## index.html
<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
<input type="text" id="par1">
<input type="text" id="par2">
<br>
<label for="op">연산자</label>
<select name="op" id="op">
  <option value="add">+</option>
  <option value="subtract">-</option>
  <option value="multiply">*</option>
  <option value="divide">/</option>
</select>
<br>
<button onclick="send()">전송</button>
<br>
<p id="result"></p>
<script src="https://cdnjs.cloudflare.com/ajax/libs/axios/0.18.0/axios.min.js"></script>
<script>
  const send = async () => {
    let resultElem = document.getElementById("result");

    const requestData = {
      op: document.getElementById("op").value,
      par1: document.getElementById("par1").value,
      par2: document.getElementById("par2").value
    };
    try {
      const res = await axios.get(`/${requestData.op}?par1=${requestData.par1}&par2=${requestData.par2}`);
      resultElem.innerText = res.data;
    }
    catch (err) {
      resultElem.innerText = "에러 발생";
    }
  };
</script>
</body>
</html>
	package kr.hs.dgsw.calculator;

	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RequestParam;
	import org.springframework.web.bind.annotation.RestController;

	@RestController
	public class CalculatorController {

	@Autowired
	private CalculatorService calculatorService;

	@RequestMapping("/add")
	public String add(@RequestParam String par1, @RequestParam String par2) {
	return calculatorService.add(par1, par2);
	}

	@RequestMapping("/subtract")
	public String subtract(@RequestParam String par1, @RequestParam String par2) {
	return calculatorService.subtract(par1, par2);
	}

	@RequestMapping("/multiply")
	public String multiply(@RequestParam String par1, @RequestParam String par2) {
	return calculatorService.multiply(par1, par2);
	}

	@RequestMapping("/divide")
	public String divide(@RequestParam String par1, @RequestParam String par2) {
	return calculatorService.divide(par1, par2);
	}
	}
	package kr.hs.dgsw.calculator;

	public interface CalculatorService {
	String add(String par1, String par2);
	String subtract(String par1, String par2);
	String multiply(String par1, String par2);
	String divide(String par1, String par2);
	}
	package kr.hs.dgsw.calculator;

	import org.springframework.stereotype.Service;

	@Service
	public class CalculatorServiceImpl implements CalculatorService {
	@Override
	public String add(String par1, String par2) {
	return "계산 결과: " + (Integer.parseInt(par1) + Integer.parseInt(par2));
	}

	@Override
	public String subtract(String par1, String par2) {
	return "계산 결과: " + (Integer.parseInt(par1) - Integer.parseInt(par2));
	}

	@Override
	public String multiply(String par1, String par2) {
	return "계산 결과: " + (Integer.parseInt(par1) * Integer.parseInt(par2));
	}

	@Override
	public String divide(String par1, String par2) {
	return "계산 결과: " + (Integer.parseInt(par1) / Integer.parseInt(par2));
	}
	}
	<!doctype html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport"
	content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>Document</title>
	</head>
	<body>
	<input type="text" id="par1">
	<input type="text" id="par2">
	<br>
	<label for="op">연산자</label>
	<select name="op" id="op">
	<option value="add">+</option>
	<option value="subtract">-</option>
	<option value="multiply">*</option>
	<option value="divide">/</option>
	</select>
	<br>
	<button onclick="send()">전송</button>
	<br>
	<p id="result"></p>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/axios/0.18.0/axios.min.js"></script>
	<script>
	const send = async () => {
	let resultElem = document.getElementById("result");

	const requestData = {
	op: document.getElementById("op").value,
	par1: document.getElementById("par1").value,
	par2: document.getElementById("par2").value
	};
	try {
	const res = await axios.get(`/${requestData.op}?par1=${requestData.par1}&par2=${requestData.par2}`);
	resultElem.innerText = res.data;
	}
	catch (err) {
	resultElem.innerText = "에러 발생";
	}
	};
	</script>
	</body>
	</html>