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
  • 11340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
/* A4mSJ6K]  
**SiteFileFetch.java kVS?RHR  
*/ Pgp {$ID  
package NetFox; 9tg)Mo%  
import java.io.*; /( 6|{B  
import java.net.*; W >(vYU  
j*;N\;iL!*  
EN !?:RV  
public class SiteFileFetch extends Thread { !8tS|C#2  
insY(.N  
+[ .Yy  
SiteInfoBean siteInfoBean = null; //文件信息Bean x6'^4y])  
long[] nStartPos; //开始位置 q1k{  
long[] nEndPos; //结束位置 _w ]4~V9  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 YH:8<O,{-  
long nFileLength; //文件长度 FnHi(S|A  
boolean bFirst = true; //是否第一次取文件 8X?>=tl  
boolean bStop = false; //停止标志 %G3sjnI;l  
File tmpFile; //文件下载的临时信息 xeTgV&$@  
DataOutputStream output; //输出到文件的输出流 l|/:Ot  
Z"I/ NGiU  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) MQcr^Y_  
public SiteFileFetch(SiteInfoBean bean) throws IOException |Wj;QO$C  
{ \0FT!} L  
siteInfoBean = bean; ~9$X3.+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); o'%e I  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); } PeZO!K  
if(tmpFile.exists ()) mE#nU(+Ta  
{ s* j fMY  
bFirst = false; BC\S/5~k  
read_nPos(); l!IKUzt)7  
} \.s`n2.w  
else ,R wfp=*E  
{ s.jO<{  
nStartPos = new long[bean.getNSplitter()]; ,7d|O}B  
nEndPos = new long[bean.getNSplitter()]; o`r(`6@  
} G { mC7@  
v vE\  
mxqG-*ch-  
?n'O Fpd  
} 8}BBOD  
PoD^`()FR{  
'=cKU0 G#  
public void run() X,v4d~>]  
{ msk/p>{O  
//获得文件长度 yi!`V.  
//分割文件 keqcV23k  
//实例FileSplitterFetch p/]s)uYp$  
//启动FileSplitterFetch线程 %"Db?  
//等待子线程返回 2'{}<9  
try{ s\0Ko1  
if(bFirst) @%W]".*'}  
{ Yr&Ka:  
nFileLength = getFileSize(); ;rBp1[qVe  
if(nFileLength == -1)  ,-rB=|w  
{ -p# ,5}  
System.err.println("File Length is not known!"); z \?UGxu}  
} t%+$" nP  
else if(nFileLength == -2) G?V"SU.  
{ Dl;d33  
System.err.println("File is not access!"); KAb(NZK  
} E8-53"m  
else YL5>V$i  
{ y @apJ;_R-  
for(int i=0;i<nStartPos.length;i++) F!8=FTb  
{ ^ @.G,u  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Gq]d:-7l  
}  H+cNX\,  
for(int i=0;i<nEndPos.length-1;i++) ` Q9+k<  
{ g#W_S?  
nEndPos = nStartPos[i+1]; T{ -2fp8r[  
} 3eg5oAZ)G8  
nEndPos[nEndPos.length-1] = nFileLength;  ^Omfe  
} |f NMs  
} |Cf mcz(56  
=,Ttw>   
-i_En^Fi  
//启动子线程 ~b8a^6:R"  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lfy7w|  
for(int i=0;i<nStartPos.length;i++) AQ@v>wr}  
{ NJ$e6$g)  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), koH4~m{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %D^bah f  
nStartPos,nEndPos,i); &`@M8-m#F  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /4C`k=>  
fileSplitterFetch.start(); %ejeyc  
} 3Xdn62[&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ="B n=>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .5g}rxO8  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ",  `$-lL"  
nEndPos = " + nFileLength); sb'p-Mj  
// fileSplitterFetch[nPos.length-1].start(); aJ2H.E  
wD=am  
R{<Y4C2~  
//等待子线程结束 2z-$zB<vyw  
//int count = 0; %c1FwAC  
//是否结束while循环 z~.9@[LG]  
boolean breakWhile = false; F aWl,}]  
37K U~9-A  
T}2:.Hk:N  
while(!bStop) 7!- \L7<  
{ $- w5o`e  
write_nPos(); eU~?p|Np  
Utility.sleep(500); ve%l({  
breakWhile = true; S OI)/u  
&"AQ; %&N  
 ^Fp=y,D  
for(int i=0;i<nStartPos.length;i++) ,o)4p\nV  
{ VR v02m5  
if(!fileSplitterFetch.bDownOver) D-iUN  
{ lJj&kVHb  
breakWhile = false; MOLO3?H(  
break; #HDesen  
} !Mil?^  
} tw86:kYEz  
if(breakWhile) S.]MOB dt  
break; q u:To7  
%Qd3BZ  
ZeTL$E[E}  
//count++; -aN":?8(G  
//if(count>4) irmwc'n]  
// siteStop(); 3k{c$x}  
} ._ih$=   
^^ j/  
_3U|2(E  
System.err.println("文件下载结束!"); l4Y1(  
} "7?t)FOo  
catch(Exception e){e.printStackTrace ();} xSOoIsL[  
} 2H>aC wfX  
t 2G1[j!  
u#VweXyU  
//获得文件长度 8GW ut=D  
public long getFileSize() D1! {S7  
{ 1t%<5O;R  
int nFileLength = -1;  wQw-:f-  
try{ `uhL61cMp  
URL url = new URL(siteInfoBean.getSSiteURL()); .$^wy3:F"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CLktNR(45  
httpConnection.setRequestProperty("User-Agent","NetFox"); c 85O_J  
r_=p,#}#  
.m!s". ?[  
int responseCode=httpConnection.getResponseCode(); ?N2X)Y@yi  
if(responseCode>=400) @>CG3`?}  
{ c&A]pLn+x  
processErrorCode(responseCode); s+N^PX3  
return -2; //-2 represent access is error d v[\.T`LY  
} uegb;m  
:Lc3a$qtx5  
F_ _H(}d  
String sHeader; mf~Lzp  
X,&xhSzg?  
-sx-7LKi  
for(int i=1;;i++) VlV)$z_  
{ excrXx  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tPzM7 n|  
//Utility.log(in.readLine()); bCt_y R  
sHeader=httpConnection.getHeaderFieldKey(i); w0$R`MOR+  
if(sHeader!=null) w@2~`<Hk'"  
{ #B\B(y  
if(sHeader.equals("Content-Length")) j^rYFS w:Q  
{ F;X"3F.!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %p}qO^%M  
break; ha5 bD%  
} |9x%gUm  
} Ef-a4Pi  
else BQuRHi IV  
break; f{f_g8f[  
} -t%L#1k  
} CR.bMF}  
catch(IOException e){e.printStackTrace ();} 0|GpZuGO9  
catch(Exception e){e.printStackTrace ();} a2[ 8wv1  
$xQ"PJ2  
 srvYAAE  
Utility.log(nFileLength); | [p68v>  
"zXGp7Q'#  
OM1*Iy  
return nFileLength; m^5s >hUl  
} *|@+rbjVC  
|zT%$  
*WD;C0?z  
//保存下载信息(文件指针位置) ,v|CombIc.  
private void write_nPos() v)%[  
{ [Yn;G7cK  
try{ N*HH,m&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); u1wg C#  
output.writeInt(nStartPos.length); Ko]QCLL  
for(int i=0;i<nStartPos.length;i++) 8>2&h  
{ `~0P[>|+  
// output.writeLong(nPos); zU=YNrn  
output.writeLong(fileSplitterFetch.nStartPos); l#p }{  
output.writeLong(fileSplitterFetch.nEndPos); KQ-,W8Q5  
} p|b+I"M  
output.close(); <r0.ppgY  
} ~@[(U!G  
catch(IOException e){e.printStackTrace ();} 9=H}yiJz  
catch(Exception e){e.printStackTrace ();} F [r|Y-c]  
} _`slkw P.  
d\\r_ bGW  
Ck:#1-t8{  
//读取保存的下载信息(文件指针位置) ?VUgwP_=  
private void read_nPos() ,9F*96  
{ uAc@ Z-  
try{ IPwj_jvw  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZK%Kgk[\:~  
int nCount = input.readInt(); QCVsVG!sN  
nStartPos = new long[nCount]; ,I/2.Q})[  
nEndPos = new long[nCount]; <g] ou YHZ  
for(int i=0;i<nStartPos.length;i++) l t&$8jh  
{ OTnu{<.a  
nStartPos = input.readLong(); %3ou^mcj  
nEndPos = input.readLong(); _E3U.mV  
} 0S%tsXt+  
input.close(); {qJHL;mP:8  
} Sb'N];  
catch(IOException e){e.printStackTrace ();} ULV)0SB  
catch(Exception e){e.printStackTrace ();} G`9cd\^  
} Cc@=?  
]d[Rf$>vu0  
#4Dn@Gqh.Y  
private void processErrorCode(int nErrorCode) |if~i;VKL  
{ w:ORmR .p  
System.err.println("Error Code : " + nErrorCode); bl$+8 !~  
} '.=Wk^,Ua  
I93 ~8wQ  
W^5<XX,ON  
//停止文件下载 X\o/i\ C}  
public void siteStop() -J-3_9I  
{ }DJ|9D^yf  
bStop = true; 0m]~J_   
for(int i=0;i<nStartPos.length;i++) A*G )CG  
fileSplitterFetch.splitterStop(); Lhl$w'r  
cxAViWsf  
MF f05\aDu  
} cWgbd^J  
} ?SB[lbU  
//负责部分文件的抓取  $&ex\_W  
**FileSplitterFetch.java sI^@A=.@  
*/ $,8CH)w  
package NetFox; R;0W+!fE  
ZM dM_i?  
oq=?i%'>  
import java.io.*; sKe9at^E]>  
import java.net.*; `Ev A\f  
NFrNm'v  
A2}Z *U(;  
public class FileSplitterFetch extends Thread { fBHkLRFH  
fR+Ov8PCq  
6V.awg,  
String sURL; //File URL MV Hz$hyB  
long nStartPos; //File Snippet Start Position l81&[  
long nEndPos; //File Snippet End Position 6(ka"Vu~  
int nThreadID; //Thread's ID &>&dhdTQ  
boolean bDownOver = false; //Downing is over R59e&   
boolean bStop = false; //Stop identical g4~X#}:z$O  
FileAccessI fileAccessI = null; //File Access interface VQ1?Db(_2  
54`bE$:+  
&:;/]cwj  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H arFo  
{ 3X88x-3  
this.sURL = sURL; *,O :>Z5I  
this.nStartPos = nStart; +O;OSZ  
this.nEndPos = nEnd; TSc~$Q]  
nThreadID = id; }}kS~ w-#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A6@+gP<  
} C ffTv  
UgF)J  
%Nwyx;>9^K  
public void run() )![f\!'PI  
{ o8~f   
while(nStartPos < nEndPos && !bStop) I ybl;u  
{ &*jxI[  
[_g#x(=  
1TK #eU  
try{ fK)ZJ_?w,@  
URL url = new URL(sURL); ()+jrrK  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c,6<7  
httpConnection.setRequestProperty("User-Agent","NetFox"); sh',"S#=@  
String sProperty = "bytes="+nStartPos+"-"; L#t-KLJ  
httpConnection.setRequestProperty("RANGE",sProperty); 2 ||KP|5@  
Utility.log(sProperty); R-g>W  
M!xm1-,[  
(hhdbf  
InputStream input = httpConnection.getInputStream(); 5@w'_#!)  
//logResponseHead(httpConnection); BxSk%$J  
C5:dO\?O  
hW0,5>[7%  
byte[] b = new byte[1024]; Ff)~clIK '  
int nRead; adRNrt*!  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r6O7&Me<  
{ "ay,Lr  
nStartPos += fileAccessI.write(b,0,nRead); e.3sAUHZ-  
//if(nThreadID == 1) 5~`|)~FA  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IQ(]66c ,  
} $Nt=gSWw5  
#Qtg\X  
+Op%,,Db  
Utility.log("Thread " + nThreadID + " is over!"); >)AE |j`  
bDownOver = true; /tId#/Y  
//nPos = fileAccessI.write (b,0,nRead); beN>5coP%A  
} "6`)vgI~  
catch(Exception e){e.printStackTrace ();} wu&|~@_s@  
} 'T&=$9g7  
} ? e9XVQ*  
+WV_`Rx#  
Ux%\Y.PPI  
//打印回应的头信息 ^'C,WZt  
public void logResponseHead(HttpURLConnection con) o+if%3  
{ 4e(9@OLP  
for(int i=1;;i++) ;qMnO_ E  
{ eI/\I:G{f  
String header=con.getHeaderFieldKey(i); Rk437vQD,  
if(header!=null) \dp9@y[^  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yZj}EBa  
Utility.log(header+" : "+con.getHeaderField(header)); ;qT!fuN;  
else (!XYH@Mz<w  
break; JR? )SGB  
} i(&6ys5  
} j{7ilo(i  
C]\^B6l<  
 H3/Y  
public void splitterStop() RAD4q"}k  
{ X-G~/n-x  
bStop = true; ])$. "g  
} v)C:E9!|  
={mPg+Ei'  
(IoPU+1b  
} y:hCBgc;`c  
|`q)/ 08b  
% L %1g  
/* iS:PRa1  
**FileAccess.java rr07\;  
*//文件访问(定位,写) FkJ>]k  
package NetFox; 0w'y#U)&8  
import java.io.*; xu_XX#9?b  
U'h[ {ek  
_ RT"1"r  
public class FileAccessI implements Serializable{ JucxhjV#,  
!q=Q~ea  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P$(iB.&  
RandomAccessFile oSavedFile; [c KI0  
long nPos; f)AW! /  
}]39 iK`w  
v8'`gY  
public FileAccessI() throws IOException y3@x*_K8  
{ jOm&yX  
this("",0); mP5d!+[8  
} Ch \ed|u  
{'c%#\  
WDH[kJ  
public FileAccessI(String sName,long nPos) throws IOException #8Id:56  
{ z!1/_]WJ,  
oSavedFile = new RandomAccessFile(sName,"rw"); E-tNB{r@  
this.nPos = nPos; +Qi52OG  
oSavedFile.seek(nPos); @8Q+=abz  
} +SuUI-.  
ku[=QsMv  
X>@.-{6T  
public synchronized int write(byte[] b,int nStart,int nLen) o trTrh  
{ gGiV1jN _  
int n = -1; #*>7X>,J  
try{ @k:f}-t  
oSavedFile.write(b,nStart,nLen); :AqnWy  
n = nLen; 1 <qVN'[  
} xo)?XFM2  
catch(IOException e) 1n"+~N^\  
{ .2{C29g  
e.printStackTrace (); V=l Q}sBY  
} Lm*LJ_+ B  
53u.p c  
kq1M <lk  
return n; |q!2i  
} N5w]2xz!  
)q]j?Z.  
G|PIH#  
} $ Op/5j  
HDW\S#  
1:;&wf  
/* WJFTy+bD  
**SiteInfoBean.java qq9tBCk  
*/ RP@idz  
package NetFox; t 1RwB23  
8#Z\}gGz  
%dk$K!5D0  
public class SiteInfoBean { ^qzT5W\@  
MlC-Aad(  
K` _E>k  
private String sSiteURL; //Site's URL gH{\y5%rO  
private String sFilePath; //Saved File's Path [>Kxm  
private String sFileName; //Saved File's Name zk 'e6  
private int nSplitter; //Count of Splited Downloading File 7dg 5HH  
nxh/&%  
C@?e`=9(  
public SiteInfoBean() %`T^qh_dE  
{//nSplitter的缺省值为5 h&)vdCCk  
//default value of nSplitter is 5 :jKXKY+T  
this("","","",5); z`r4edk3  
} *}iT6OJ  
%C E@}  
o2e h)rtB  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ko]h r  
{ tv=FFfQ  
sSiteURL= sURL; {}_Oo%IVGK  
sFilePath = sPath; n,Mw# r?y  
sFileName = sName; k}0  
this.nSplitter = nSpiltter; eUw;!Du  
(zLIv9$  
q!oZ; $  
} 4#7@KhK}  
g`8 mh&u%  
~ {7N TW  
public String getSSiteURL() 2|NyAtPb5  
{ k;:u| s8NS  
return sSiteURL; 36Z`.E>~L  
} ^nm!NL{z^  
B oj{+rE0  
owY_cDzrH  
public void setSSiteURL(String value) \7tvNa,C  
{ }9Dv\"t5  
sSiteURL = value; {FmFu$z+[  
} u/:Sf*;?  
"vRqtEBO@  
gMK3o8B/  
public String getSFilePath() #/v_ h6$  
{ Y)5uK:)^  
return sFilePath; rnBeL _8C  
} 4a\+o]  
]jY)M<:J4  
n]{}C.C=  
public void setSFilePath(String value) N8(x),  
{ .Zt/e>K&  
sFilePath = value; 0JRB Nh  
} v*]Xur6e}  
YK+Z0ry  
.6/p4OR|  
public String getSFileName() |2&mvjk@H  
{ gLxy RbVI  
return sFileName; hE#8_34%s  
} x w83K  
WI 4_4  
S"A_TH  
public void setSFileName(String value) C`_D{r  
{ 5F+ f'~  
sFileName = value; !<PTsk F  
} Z6AU%3]  
L8K3&[l%  
l3|>*szX  
public int getNSplitter() MmX[xk  
{ R]s jG <  
return nSplitter; m1; <T@  
} k 5r*?Os  
v;qL? _:=c  
vHe.+XY  
public void setNSplitter(int nCount) F"#*8P  
{ WIl S^?5I<  
nSplitter = nCount; J& SuUh<  
} z}N^`_ *  
} ~4` ec   
2}Plr{s9  
AX Jj"hN  
/* *ik)>c_  
**Utility.java B=/=U7T  
*/ &>4$ [m>n  
package NetFox; 9U1!"/F  
`l0icfy  
GeT CN  
public class Utility { +hhbp'%  
I%*Z j,>  
IX3 yNTW"L  
public Utility() um;U;%?Q  
{ pG=zGx4  
s"F,=]HQ!G  
oqo8{hrdHk  
} )4~XZt1r  
Jpnp'  
//线程睡眠 .@Sh,^v  
public static void sleep(int nSecond) vjWgR9 4/{  
{ / ^M3-5@Q  
try{ XxQ2g&USk  
Thread.sleep(nSecond); =,Um;hU3r  
} a #**96Av  
catch(Exception e) #^w 1!xXD  
{ +mPB?5  
e.printStackTrace (); }slEkpk? ]  
} '~=xP  
} ky"7 ^  
fb=vO U  
//日志 l{ { #tW  
public static void log(String sMsg) X KeK;+  
{ EqwA8? M  
System.err.println(sMsg); OU=IV;V{  
} = $Yk8,  
OVK(:{PwS  
C>-"*Lt  
public static void log(int sMsg) ~a)2 0  
{ r|$g((g  
System.err.println(sMsg); "d*  
} dQ o$^?  
} > _) a7%  
\05C'z3]  
KA[Su0  
/* ~z"->.u  
**TestMethod.java x6P^IkL:  
*/ 2!`Z3>Oa  
package NetFox; A[Xw|9  
cW>`Z:6{K  
:9>nY  
public class TestMethod {  F<1'M#bl  
Ho9*y3]  
~_6rD`2cJ  
public TestMethod() yZ6X$I:C  
{ ///xx/weblogic60b2_win.exe PSvRO% &  
try{ nI` 1@ vB&  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @72G*u\Wz  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0(.C f.B~  
SiteFileFetch fileFetch = new SiteFileFetch(bean); of<OOh%3  
fileFetch.start(); zy5bDL -  
} }0*7bb  
catch(Exception e){e.printStackTrace ();} a#@ opUn-  
|LhuZ_;1xo  
V6o,}o&-  
} R'_[RHFC  
}zLE*b,  
z}|'&O*.F  
public static void main(String[] args) }:A kpm  
{ WV5R$IqY  
new TestMethod(); HKf3eC  
} ? -tw*2+  
} {K}+$jzGVt  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
10+5=?,请输入中文答案:十五