如果我贷款买一套 400W 的房子，我要给银行多送几辆迈巴赫？
买房攻略
2023 年至今，上海房价一跌再跌。俺已经蠢蠢欲动了，磨刀霍霍向"买房"。但是奈何手里钞票不够，只能向天再借 500 年打工赚钱。但是作为倔强的互联网打工人，想知道自己会被银行割多少韭菜。于是就写了个程序，用于计算我贷款买房需要多给银行还多少钱。这样我就能知道银行割我的韭菜，能省下几辆迈巴赫的钱了。
贷款利率
- 公积金的贷款利率。
- 首房：贷款时间 <=5 年，利率为 2.6% ；贷款时间 >= 5 年，利率为 3.1% 。
- 非首房：贷款时间 <=5 年，利率为 3.025% ；贷款时间 >= 5 年，利率为 3.575% 。
- 商业险贷款利率
- 贷款时间 <=5 年，利率为 3.45% ；贷款时间 >= 5 年，利率为 3.95% 。
代码实现
- 以下代码，实现了：我贷款买房需要多给银行还多少钱。
public class LoanAmountCalculation {
//首套住房5年以内公积金贷款利率
private static final double FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_WITHIN_FIVE_YEARS = 2.6;
//首套住房5年以上公积金款利率
private static final double FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_MORE_FIVE_YEARS = 3.1;
//二房5年以内公积金贷款利率
private static final double NOT_FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_WITHIN_FIVE_YEARS = 3.025;
//二房5年以上公积金款利率
private static final double NOT_FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_MORE_FIVE_YEARS = 3.575;
//5年以内商业贷款利率
private static final double COMMERCIAL_LOAN_RATE_WITHIN_FIVE_YEARS = 3.45;
//5年以上商业贷款利率
private static final double COMMERCIAL_LOAN_RATE_MORE_FIVE_YEARS = 3.95;
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
double houseAmount = getInputValue(scanner, "请输入预计买房金额(单位:W)：", "请输出正确的买房金额（>0）！");
double principal = getInputValue(scanner, "请输入您的本金(单位:W)：", "请输出正确的买房金额（>0）！");
if (principal >= houseAmount) {
System.out.println("全款买房，崇拜大佬！");
return;
}
double accumulationFundLoanAmount = getInputValue(scanner, "请输入公积金贷款金额(单位:W)：", "请输出正确的公积金贷款金额（>0）！");
double commercialLoanAmount = houseAmount - principal - accumulationFundLoanAmount;
if(commercialLoanAmount <= 0){
System.out.println("您的本金+公积金贷款已经够买房啦，恭喜大佬！");
return;
}else{
System.out.println("您的本金+公积金贷款还不够买房哦，需要商业贷款金额为(单位:W)：" + commercialLoanAmount + "\n");
}
int accumulationFundLoanYears = getInputIntValue(scanner, "请输入公积金贷款年份(单位:年)：");
int commercialLoanAmountYears = getInputIntValue(scanner, "请输入商业贷款年份(单位:年)：");
int isFirstHouse = getInputIntValue(scanner, "请输入是否首房(0:否，1：是)：");
LoanAmount loanAmount = calculateLoanAmount(
accumulationFundLoanAmount, accumulationFundLoanYears,
commercialLoanAmount, commercialLoanAmountYears, isFirstHouse);
System.out.println("详细贷款信息如下：" + "\n" + loanAmount);
}
/**
* 获取double类型的输入
* @param scanner：Java输入类
* @param prompt：提示信息
* @param errorMessage：输入错误的提示信息
* @return 一个double类型的输入
*/
private static double getInputValue(Scanner scanner, String prompt, String errorMessage) {
double value;
while (true) {
System.out.println(prompt);
if (scanner.hasNextDouble()) {
value = scanner.nextDouble();
if (value > 0) {
break;
} else {
System.out.println(errorMessage);
}
} else {
scanner.next();
System.out.println(errorMessage);
}
}
return value;
}
/**
* 获取int类型的输入
* @param scanner：Java输入类
* @param prompt：提示信息
* @return 一个int类型的输入
*/
private static int getInputIntValue(Scanner scanner, String prompt) {
int value;
while (true) {
System.out.println(prompt);
if (scanner.hasNextInt()) {
value = scanner.nextInt();
if (value > 0) {
break;
} else {
System.out.println("请输入正确的年份（>0）！");
}
} else {
scanner.next();
System.out.println("请输入正确的年份（>0）！");
}
}
return value;
}
/**
* 功能：贷款金额计算
* 入参：
* 1.accumulationFundLoanAmount：公积金贷款金额 2.accumulationFundLoanYears：公积金贷款年份；
* 3.commercialLoanAmount：商业贷款金额； 4.commercialLoanAmountYears：商业贷款年份
* 5.isFirstHouse：是否首房
*/
private static LoanAmount calculateLoanAmount(double accumulationFundLoanAmount, int accumulationFundLoanYears,
double commercialLoanAmount, int commercialLoanAmountYears, int isFirstHouse){
LoanAmount loanAmount = new LoanAmount();
//公积金贷款还款金额
double accumulationFundRepaymentAmount;
if(isFirstHouse == 1){
accumulationFundRepaymentAmount = accumulationFundLoanYears <= 5 ?
accumulationFundLoanAmount * Math.pow((100 + FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_WITHIN_FIVE_YEARS) / 100, accumulationFundLoanYears)
: accumulationFundLoanAmount * Math.pow((100 + FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_MORE_FIVE_YEARS) / 100, accumulationFundLoanYears);
}else{
accumulationFundRepaymentAmount = accumulationFundLoanYears <= 5 ?
accumulationFundLoanAmount * Math.pow((100 + NOT_FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_WITHIN_FIVE_YEARS) / 100, accumulationFundLoanYears)
: accumulationFundLoanAmount * Math.pow((100 + NOT_FIRST_HOUSE_ACCUMULATION_FUND_LOAN_RATE_MORE_FIVE_YEARS) / 100, accumulationFundLoanYears);
}
loanAmount.setAccumulationFundRepaymentAmount(String.format("%.2f", accumulationFundRepaymentAmount));
//公积金贷款每年还款金额
loanAmount.setAccumulationFundAnnualRepaymentAmount(String.format("%.2f", accumulationFundRepaymentAmount / accumulationFundLoanYears));
//商业贷款还款金额
double commercialRepaymentAmount = commercialLoanAmountYears <= 5 ?
commercialLoanAmount * Math.pow((100 + COMMERCIAL_LOAN_RATE_WITHIN_FIVE_YEARS) / 100, commercialLoanAmountYears)
: commercialLoanAmount * Math.pow((100 + COMMERCIAL_LOAN_RATE_MORE_FIVE_YEARS) / 100, commercialLoanAmountYears);
loanAmount.setCommercialRepaymentAmount(String.format("%.2f", commercialRepaymentAmount));
//商业贷款每年还款金额
loanAmount.setCommercialAnnualRepaymentAmount(String.format("%.2f", commercialRepaymentAmount / commercialLoanAmountYears));
//公积金贷款超出金额
loanAmount.setAccumulationFundLoanExceedAmount(String.format("%.2f", accumulationFundRepaymentAmount - accumulationFundLoanAmount));
//商业贷款超出金额
loanAmount.setCommercialLoanExceedAmount(String.format("%.2f", commercialRepaymentAmount - commercialLoanAmount));
loanAmount.setTotalExceedLoanAmount(String.format("%.2f", accumulationFundRepaymentAmount - accumulationFundLoanAmount + commercialRepaymentAmount - commercialLoanAmount));
return loanAmount;
}
@Data
static class LoanAmount{
/**
* 公积金贷款还款金额
*/
private String accumulationFundRepaymentAmount;
/**
* 公积金贷款每年还款金额
*/
private String accumulationFundAnnualRepaymentAmount;
/**
* 商业贷款还款金额
*/
private String commercialRepaymentAmount;
/**
* 商业贷款每年还款金额
*/
private String commercialAnnualRepaymentAmount;
/**
* 公积金贷款超出金额 = 公积金贷款还款金额 - 公积金贷款金额
*/
private String accumulationFundLoanExceedAmount;
/**
* 商业贷款超出金额 = 商业贷款还款金额 - 商业贷款金额
*/
private String commercialLoanExceedAmount;
/**
* 总共贷款超出金额
*/
private String totalExceedLoanAmount;
@Override
public String toString() {
return "1.公积金贷款还款金额=" + accumulationFundRepaymentAmount + "万元\n" +
"2.商业贷款还款金额=" + commercialRepaymentAmount + "万元\n" +
"3.公积金贷款每年还款金额=" + accumulationFundAnnualRepaymentAmount + "万元\n" +
"4.商业贷款每年还款金额=" + commercialAnnualRepaymentAmount + "万元\n" +
"5.公积金贷款超出金额=" + accumulationFundLoanExceedAmount + "万元\n" +
"6.商业贷款超出金额=" + commercialLoanExceedAmount + "万元\n" +
"7.总共贷款超出金额=" + totalExceedLoanAmount + "万元\n";
}
}
}
代码输入，输出示例
由上图可知，我要贷款买一套 400w 的房子，本金只有 120w，使用组合贷：公积金贷款 120w（10年），商业贷款 160w（20年）。最终我需要多还银行 230.07w，相当于买两辆迈巴赫的钱了，巨亏！
以上就是全部内容了，如果涉及到真实场景，还是需要根据具体的情况计算的！
作者：一只野生的八哥
来源：juejin.cn/post/7346385551366684722
来源：juejin.cn/post/7346385551366684722
