社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 11612阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* lz#@_F|.*  
**SiteFileFetch.java unN*L  
*/ kkT=g^D9j  
package NetFox; |JUAR{  
import java.io.*; $L]E< gWrP  
import java.net.*; 1[Jv9S*f/  
_>{"vY  
y<8o!=Tb5  
public class SiteFileFetch extends Thread { @A%\;o o  
#@uF?8u  
2+\@0j[q  
SiteInfoBean siteInfoBean = null; //文件信息Bean 59_VC('  
long[] nStartPos; //开始位置 eGrxS;NY  
long[] nEndPos; //结束位置 @7Nc*-SM  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Y-"7R>^I  
long nFileLength; //文件长度 0ARj3   
boolean bFirst = true; //是否第一次取文件 VsRdZ4  
boolean bStop = false; //停止标志 [k,FJ5X  
File tmpFile; //文件下载的临时信息 _~b]/]|z#N  
DataOutputStream output; //输出到文件的输出流 2s`~<EF N  
wcDb| H&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) w}(Ht_6q{  
public SiteFileFetch(SiteInfoBean bean) throws IOException HO8x:2m  
{ A0uA\E4q  
siteInfoBean = bean; d a.6Z!a  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); c~Z\|Y`#B  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ^ G>/;mZ  
if(tmpFile.exists ()) Jy#2 1  
{ u6p nO  
bFirst = false; PKNpR  
read_nPos(); v<S?"# ]F=  
} hjoxx F\_  
else nTXM/  
{ F='rGQK!1  
nStartPos = new long[bean.getNSplitter()]; }mQh^  
nEndPos = new long[bean.getNSplitter()]; 7|7sA'1 cM  
} C@FX[:l@-  
rWzO> v  
[YQ` `  
?pp|~A)b  
} i<uk}  
\kksZ4,  
]`n6H[6O  
public void run() y{uN+QS  
{ x5nw/''[2  
//获得文件长度 f5|Ew&1EP  
//分割文件 e^Lt{/  
//实例FileSplitterFetch )XL}u4X  
//启动FileSplitterFetch线程 hX sH9R  
//等待子线程返回 %N-f9o8  
try{ T,Zfz9{n  
if(bFirst) y e1hcQ  
{ U6R~aRJ;  
nFileLength = getFileSize(); _,9/g^<  
if(nFileLength == -1) 6`hHx=L  
{ o;Ma)/P  
System.err.println("File Length is not known!"); 9"mcN3x:\e  
} 1Igo9rv  
else if(nFileLength == -2) _0]{kB.$_  
{ hiA%Tq?  
System.err.println("File is not access!"); lip1wR7  
} h4dT N}  
else 9-?[%8  
{ h$y0>eMWs  
for(int i=0;i<nStartPos.length;i++) )'gO?cN  
{ C'jE'B5b  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Qh. : N  
} J+6bp0RIh  
for(int i=0;i<nEndPos.length-1;i++) /6@Wm? `DB  
{ H- aSLc  
nEndPos = nStartPos[i+1]; C~aNOe WR  
} } h pTS_  
nEndPos[nEndPos.length-1] = nFileLength; Y^W.gGM  
} $s-HG[lX[  
} Z39I*-6F9W  
]@MBE1M  
c'r7sI%Yi  
//启动子线程 qdeS*r p\  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -P>f2It  
for(int i=0;i<nStartPos.length;i++) w- .=u3  
{ m"Y|xvIA  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  B Ji  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2K1odqO#   
nStartPos,nEndPos,i); 2m/=0sb\{  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'v*Y7zZ#K  
fileSplitterFetch.start(); .U:DuyT  
} [J.-gN$X@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zS##YR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m;"i4!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =9ISsI\Y6  
nEndPos = " + nFileLength); D.\s mk  
// fileSplitterFetch[nPos.length-1].start(); : {Crc   
fhZD#D  
;0f?-W?1  
//等待子线程结束 'YcoF;&[C  
//int count = 0; On{p(| l  
//是否结束while循环 (X"WEp^Q{I  
boolean breakWhile = false; Gf{FFIe(  
AK*F,H9  
U0kEhMIIf  
while(!bStop) _jW}p-j  
{ TZ,kmk#  
write_nPos(); szy^kj^2  
Utility.sleep(500); b8@gv OB  
breakWhile = true; s-He  
hh!^^emo  
.w`1;o  
for(int i=0;i<nStartPos.length;i++) aI6fPQe  
{ ['SZe0  
if(!fileSplitterFetch.bDownOver) &91U(Go  
{ k*8 ld-O  
breakWhile = false; HjO-6F#s  
break; loLN ~6  
} L[Dr[  
} Ws;}D}+  
if(breakWhile) aQK>q. t  
break; 2vit{  
PfI~`ke  
buRK\C  
//count++; y0R5YCq\":  
//if(count>4) t(|\3$z  
// siteStop(); x]gf3Tc58  
} 9(>l trA  
S"Dw8_y7}  
c bk|LQ.O  
System.err.println("文件下载结束!"); ? D?XaRb  
} D e>'  
catch(Exception e){e.printStackTrace ();} "@JSF  
} xsq+RBJi  
3UIR^Rh+  
gt9{u"o  
//获得文件长度 luyU!  
public long getFileSize() +a%Vp!y  
{ RQZ|:SvV  
int nFileLength = -1; F;mK)Q-  
try{ }?pY~f  
URL url = new URL(siteInfoBean.getSSiteURL()); HY,+;tf2r  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z2]ySyt]  
httpConnection.setRequestProperty("User-Agent","NetFox"); `2X#;{a:  
c8cV{}7Kb  
]Hp o[IF  
int responseCode=httpConnection.getResponseCode(); fXPD^}?Ux4  
if(responseCode>=400) e7<//~W7W  
{ =U6%Wdth  
processErrorCode(responseCode); S0_#h)  
return -2; //-2 represent access is error BTwLx-p9t  
} m8q3Pp  
9}{i8 <$=  
A d0dg2Gw  
String sHeader; Cc?BJ  
/ ;U  
B*+3A!{s  
for(int i=1;;i++) D2`tWRm0  
{ ic}M)S FD;  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K0#kW \4`  
//Utility.log(in.readLine()); NM0[yh  
sHeader=httpConnection.getHeaderFieldKey(i); 8#gS{   
if(sHeader!=null) lD;="b  
{ S aCa  
if(sHeader.equals("Content-Length")) BTXS+mvl  
{ [/}y!;3iXM  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qV%t[>  
break; #OKzJ"g  
} I<q=lK  
} s }]qlg  
else sbZ$h <  
break; 7a@%^G @!  
} R6ynL([xh  
} :>U2yI  
catch(IOException e){e.printStackTrace ();} %z6.}4h  
catch(Exception e){e.printStackTrace ();} '1lr "}"Q+  
1sL#XB$@N  
L~yu  
Utility.log(nFileLength); G:f\wK[  
%ec9`0^4S  
(o/HLmr@Y  
return nFileLength; S~QL x  
} x~Eg ax  
m@hmu}qz-  
WKf->W  
//保存下载信息(文件指针位置) '/^bO#G:  
private void write_nPos() 4~Ptn/ g  
{ =)Cqjp  
try{ P=:mn>  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?=:wIMV  
output.writeInt(nStartPos.length);  =#N;ZG  
for(int i=0;i<nStartPos.length;i++) VZ?"yUZ Id  
{ oyGO!j  
// output.writeLong(nPos); 3"O)"/"Q.  
output.writeLong(fileSplitterFetch.nStartPos); CKShz]1  
output.writeLong(fileSplitterFetch.nEndPos); UXz0HRRS0  
} B!|<<;Da6  
output.close(); ~c>*3*  
} -jc8ku3*  
catch(IOException e){e.printStackTrace ();} 2\flTO2Ny  
catch(Exception e){e.printStackTrace ();} ;\@co5.=  
} olNgtSX  
=Rl?. +uE  
), >jBYMJ  
//读取保存的下载信息(文件指针位置) 7 tOOruiC  
private void read_nPos() |s&jWM$  
{ <$#b3F"I  
try{ `C~RA, M  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); . z/M (  
int nCount = input.readInt(); WPBn?vb0<  
nStartPos = new long[nCount]; HS{a^c%  
nEndPos = new long[nCount]; \atztC{-L>  
for(int i=0;i<nStartPos.length;i++) BlF]-dF\  
{ W\s ]qsLS  
nStartPos = input.readLong(); =HT:p:S  
nEndPos = input.readLong(); Ys@M1o  
} ecK{+Z'G  
input.close(); box(FjrZE  
}  (f DA  
catch(IOException e){e.printStackTrace ();} G.2ij%Zz  
catch(Exception e){e.printStackTrace ();} cPh U q ET  
} p`// *gl  
Byf5~OC  
;[*jLi,uc  
private void processErrorCode(int nErrorCode) T:ye2yg  
{ /"A)}>a  
System.err.println("Error Code : " + nErrorCode); S/}6AX#F4  
} 8}m bfu o1  
:3k&[W*  
nJJ9>#<g$  
//停止文件下载 Nf0'>`/  
public void siteStop() %vjLw`  
{ Mg H,"G  
bStop = true; \%nFCK0  
for(int i=0;i<nStartPos.length;i++) `8Y& KVhu  
fileSplitterFetch.splitterStop(); +*2wGAT  
aa8xo5tIp  
gxEa?QH  
} s; 'XX}Y  
} CmaV>  
//负责部分文件的抓取 ]:CU.M1  
**FileSplitterFetch.java 2|vArRKt  
*/ > }#h  
package NetFox; F+A"-k_\T#  
BU[ .P]  
BJI}gm2y  
import java.io.*; ?CB*MWjd  
import java.net.*; mzuf l:-=  
%G6ml,  
%Z@+K_X9x  
public class FileSplitterFetch extends Thread { S<"M5e  
*I;,|Jjk  
b#U nE  
String sURL; //File URL vn"2"hPF|  
long nStartPos; //File Snippet Start Position 8spoDb.S  
long nEndPos; //File Snippet End Position 2@``=0z  
int nThreadID; //Thread's ID I@VhxJh  
boolean bDownOver = false; //Downing is over iB[>uW  
boolean bStop = false; //Stop identical tlw$/tMa  
FileAccessI fileAccessI = null; //File Access interface > Y <in/  
`ReTfz;o  
QJc3@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException TJ@@k SSbl  
{ 3F'{JP  
this.sURL = sURL; H`/Q hE  
this.nStartPos = nStart; =5NrkCk#V  
this.nEndPos = nEnd; 5'f4=J$Z)  
nThreadID = id; 7n*,L5%?]4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9-;ujl?{  
} R<VNbm;  
:'aT 4  
.Ap-<FB  
public void run() 5~T`R~Uqb  
{ v.,|#}0 o  
while(nStartPos < nEndPos && !bStop) >AsD6]  
{ )Lht}I ]:  
av>c  
E"l&<U  
try{ D>9~JHB  
URL url = new URL(sURL); tx}} Kd  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J(*q OGBD  
httpConnection.setRequestProperty("User-Agent","NetFox"); L/1zG/@  
String sProperty = "bytes="+nStartPos+"-"; l2uh"!  
httpConnection.setRequestProperty("RANGE",sProperty); (vm &&a@  
Utility.log(sProperty); sS5 ]d8  
Rk2V[R.`S  
EL!V\J`S_  
InputStream input = httpConnection.getInputStream(); DA)+)PhY7K  
//logResponseHead(httpConnection); Q3MG+@)S  
8<(qN> R  
1PWs">*(  
byte[] b = new byte[1024]; Bw-<xwD  
int nRead; T'9I&h%\  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NNZ%jJy?=,  
{ ":E^&yQ  
nStartPos += fileAccessI.write(b,0,nRead); m+p}Qi8i)  
//if(nThreadID == 1) \u@4 eBAV  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [(v?Z`cX\  
} %2Q:+6)  
OjxaA[$  
2XhtK  
Utility.log("Thread " + nThreadID + " is over!"); (9:MIP  
bDownOver = true; 6@pP aq6  
//nPos = fileAccessI.write (b,0,nRead); xW@y=l Cu  
} J2cqnwUV  
catch(Exception e){e.printStackTrace ();} Wz)O,X^  
} 0yW#).D^b  
} `>CHE'_  
fl| 8#\r  
m1@ste;$W  
//打印回应的头信息 dz fR ^Gv  
public void logResponseHead(HttpURLConnection con) (.Hiee43  
{ Wbo{v r[2+  
for(int i=1;;i++) ySP1,xq  
{ L/Cp\|~ O  
String header=con.getHeaderFieldKey(i); g_lj/u]P  
if(header!=null) "?Dov/+Q.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4|Z;EAFx  
Utility.log(header+" : "+con.getHeaderField(header)); @UCI^a~w  
else YXE?b@W"  
break; X`km\\*  
} lz>YjK:  
} ^VsX9  
~!( (?8"  
+2%ih !  
public void splitterStop() lSv?!2  
{ 2E~WcB  
bStop = true; 61|uvTX  
} Kx.'^y  
]h4^3   
:;[pl|}tM  
} yZup4#>8  
ZH8O%>!  
V<~.:G$3H  
/* <<#-IsT  
**FileAccess.java _'9("m V  
*//文件访问(定位,写) [fF0Qa-  
package NetFox; r':wq   
import java.io.*; :s8^nEK  
K)z{R n  
0zrgK;9  
public class FileAccessI implements Serializable{ DG& ({vy  
(XtN3FTY  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 eQh@.U*S)  
RandomAccessFile oSavedFile; ]IbX<  
long nPos; {"X n`@Y  
b~;gj^  
[RtTi<F^  
public FileAccessI() throws IOException @c&}\#;  
{ E6"+\-e  
this("",0); h LYy  
} [?rK9I&  
GT$.#};u  
+"8 [E~Bih  
public FileAccessI(String sName,long nPos) throws IOException )!+M\fT  
{ 8U,VpuQ:  
oSavedFile = new RandomAccessFile(sName,"rw"); E(J@A'cX  
this.nPos = nPos; /.1c <!  
oSavedFile.seek(nPos); Dqss/vwV  
} %@/"BF;r  
sywSvnPuYZ  
Hc?8Q\O:  
public synchronized int write(byte[] b,int nStart,int nLen) RbPD3& .  
{ Q]j [+e  
int n = -1; IXE`MLc  
try{ ?f@g1jJP  
oSavedFile.write(b,nStart,nLen); DONXq]f:,"  
n = nLen; ~)!yl. H  
} ~)5NX 4Po  
catch(IOException e) 8<BYAHY^  
{ #-76E  
e.printStackTrace (); vW`Dy8`06  
} "B18|#v  
L eg)q7n  
RmF,x9  
return n; \ G}02h  
} 0#\K9|.  
i?+ZrAx>  
8 xfn$  
} Y0nnn  
ITcgp K6k  
MBy0Ky  
/* L=`QF'Im  
**SiteInfoBean.java *nb `DR  
*/ <2b&AF{En  
package NetFox; F@m]Imn5Dx  
UC3&:aQ!  
7Mx F? I  
public class SiteInfoBean { Gn*cphb  
pib i#  
L{;Sc_  
private String sSiteURL; //Site's URL GYv D*?uBc  
private String sFilePath; //Saved File's Path R _#x  
private String sFileName; //Saved File's Name <( "M;C3y  
private int nSplitter; //Count of Splited Downloading File Hzm<KQ g  
jA<(#lm;  
3y&N}'R(F  
public SiteInfoBean() n7Em t$Hi>  
{//nSplitter的缺省值为5 GnAG'.t-Z  
//default value of nSplitter is 5 }XmrfegF  
this("","","",5); }kJfTsFS  
} |nOqy&B  
;Dh\2! sr  
z@bq*':~J  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ++9?LH4S4  
{ ;_$Q~X  
sSiteURL= sURL; m1pge4*  
sFilePath = sPath; )FLDCer  
sFileName = sName; PjwDth A1  
this.nSplitter = nSpiltter; r4YiXss  
&Hz{   
dh9Qo4-{  
} VtP^fM^{  
_v/w ,z  
;$a+ >  
public String getSSiteURL() !sknO53`H`  
{ D.[h`Hkc  
return sSiteURL; 9Wu c1#  
} pyHU +B  
 3o_)x  
_\/KI /  
public void setSSiteURL(String value) mS$9D{  
{ [zC1LTXe  
sSiteURL = value; CdEQiu  
} EF>vu+YK  
]|JQH  
IOfxx>=3  
public String getSFilePath() _h6j, )  
{ <QuIXA  
return sFilePath; V8w7U:K  
} 8+f{ /  
nrBpq  
} Z/[ "  
public void setSFilePath(String value) uOQ!av2"Rf  
{ RGu`Jk  
sFilePath = value; f-.dL  
} t]3> X  
J# >)+  
a/\SPXQ/9  
public String getSFileName() x5w5xw  
{ &nV/XLpG  
return sFileName; lQS(\}N  
} ^cUmLzM  
"h@=O c  
*&vlfH  
public void setSFileName(String value) 1 5heLnei  
{ ._E 6?  
sFileName = value; =,B Dd$e  
} {})d}dEC  
]Cc3}+(s  
]8n*fo2#  
public int getNSplitter() lGlh/B%  
{ qnu<"$   
return nSplitter; /IxoS  
} L[s`8u<_)z  
XnwVK  
E"O6N.}.  
public void setNSplitter(int nCount) AZ9;6Df  
{ CL|d>  
nSplitter = nCount; > `1K0?_  
} &%UZ"CcA  
} <~ Dq8If  
 ?v z[Zi  
a Xn:hn~O  
/* AqA.,;G  
**Utility.java >]L\Bw  
*/ C3K":JB  
package NetFox; !V'~<&  
}ed{8"bj  
.9u0WP95  
public class Utility { 2M+}o"g  
lC=-1*WH  
9bQD"%ha=d  
public Utility() n2(`O^yd7C  
{ ]')  
Y|l&mK?  
ynZp|'b?<  
} 1!%T<!A.  
Yu}[RXC(=  
//线程睡眠 4C#r=Uw`  
public static void sleep(int nSecond) | |u  
{ zH13 ~\  
try{ Q\nIU7:bZ  
Thread.sleep(nSecond); !X5LgMw^;  
} aBd>.]l?  
catch(Exception e) qOTo p-  
{ j5gL 67B  
e.printStackTrace (); `Hx JE"/  
} _ea|E  8  
} wX4gyr  
+h)1NX;o1  
//日志 zcy`8&{A<?  
public static void log(String sMsg) y]okOEV0  
{ S l`F`  
System.err.println(sMsg); 1 )H;}%[  
} FvJkb!5*e_  
cCuK?3V4K  
kz"QS.${  
public static void log(int sMsg) h+!@`c>)Y  
{ FfX*bqy  
System.err.println(sMsg);  9+ A~(  
} eJ0Xfw%y%T  
} FfC\uuRe  
T8BewO=}  
IvX+yU  
/* ~_F<"40  
**TestMethod.java uC! dy  
*/ `J$7X  
package NetFox; M1q_gHA  
#Y0ru9  
6u9?  
public class TestMethod { Fr_6pEH]}  
d3]<'B:nb  
>rYkVlv  
public TestMethod() P9o=G=i  
{ ///xx/weblogic60b2_win.exe >x1yFwX}-f  
try{ 7fC:' 1]G  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1=_Qj}!1  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [;Jq=G8&t  
SiteFileFetch fileFetch = new SiteFileFetch(bean); z?t75#u9.  
fileFetch.start(); 4iv&!hAc;  
} zGwM# -  
catch(Exception e){e.printStackTrace ();} oh7tE$"c  
iOtf7.@  
}Oq P`B  
} xnDst9%  
6@;sOiN+  
,FwJ0V  
public static void main(String[] args) uE}$ZBi q  
{ X>i{288M3  
new TestMethod(); cAn_:^  
} A[`2Mnj  
} !-m 'diE  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
10+5=?,请输入中文答案:十五