Java中将Base64编码字符串转换为图片有以下几种方法：
1. 使用Apache Codec库
Apache Codec库提供了一个Base64编解码的实现，可以使用它来将Base64编码字符串转换为图片。需要引入Apache Codec的Maven依赖：
commons-codec commons-codec 1.13
可以使用下面的代码将Base64编码字符串转换为图片：
// 将Base64编码字符串转换为图片
String base64String = "data:image/png;base64,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