freemarker中处理页面自动四舍五入问题

在开发中很容易忽视一点，输入一个值(可能是小数)，输出时如果不做处理，就很容易出现

隐形的BUG。比如，如果从数据库取出一个0.22的数值，一般的输出${x?if_exists?html},

这时是显示0，而不是0.22。

应该写成${x?if_exists?string.number} 或者 ${x?if_exists.toString()?html}

下面就是关于数字的具体介绍：

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<#assign x=42>

${x}

${x?string} <#-- the same as ${x} -->

${x?string.number}

${x?string.currency}

${x?string.percent}

If your locale is US English, this will certainly produce:

42

42

42

$42.00

4,200%

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<#setting number_format="currency">

<#assign x=42>

${x}

${x?string} <#-- the same as ${x} -->

${x?string.number}

${x?string.currency}

${x?string.percent}

Will now output:

$42.00

$42.00

42

$42.00

4,200%

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<#assign x = 1.234>

${x?string("0")}

${x?string("0.#")}

${x?string("0.##")}

${x?string("0.###")}

${x?string("0.####")}

${1?string("000.00")}

${12.1?string("000.00")}

${123.456?string("000.00")}

${1.2?string("0")}

${1.8?string("0")}

${1.5?string("0")} <-- 1.5, rounded towards even neighbor

${2.5?string("0")} <-- 2.5, rounded towards even neighbor

${12345?string("0.##E0")}

outputs this:

1

1.2

1.23

1.234

1.234

001.00

012.10

123.46

1

2

2 <-- 1.5, rounded towards even neighbor

2 <-- 2.5, rounded towards even neighbor

1.23E4

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<#setting number_format="0.##">

${1.234}

outputs this:

1.23