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
  • 8378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
/* uc~/l4~N  
**SiteFileFetch.java /%9Ge AAs  
*/ K|Cb6''  
package NetFox; `SfBT1#5G  
import java.io.*; ;h"St0   
import java.net.*; Z[Z3x6 6  
^ UDNp.6k  
u4KP;_,m  
public class SiteFileFetch extends Thread { #$dEg  
!T|q/ri  
X]1Q# $b  
SiteInfoBean siteInfoBean = null; //文件信息Bean }Sx+:N*  
long[] nStartPos; //开始位置 uHQf<R$:  
long[] nEndPos; //结束位置 u3k{s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W"meH~[Cp  
long nFileLength; //文件长度 Gi+ZI{)  
boolean bFirst = true; //是否第一次取文件 W2`/z)[*>  
boolean bStop = false; //停止标志 yKhN1kY  
File tmpFile; //文件下载的临时信息 0K<|>I  
DataOutputStream output; //输出到文件的输出流 Cu $mb}@  
6Trtulm  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) !H^e$BA  
public SiteFileFetch(SiteInfoBean bean) throws IOException T?4I\SG  
{ qib4DT$v-6  
siteInfoBean = bean; }o:sU^Pwa  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); } \?]uNH  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); f\vy5''  
if(tmpFile.exists ()) /\wm/Yx?S  
{ #,5v#| u|7  
bFirst = false; {/2 _"H3:  
read_nPos(); |=rb#z&  
} 3;'RF#VL  
else DGJt$o=&@  
{ xm*6I  
nStartPos = new long[bean.getNSplitter()]; 05ZF>`g*  
nEndPos = new long[bean.getNSplitter()]; 8WP|cF]  
} pIhy3@bY  
Hs#q 7  
W1\F-:4L@  
Ve9*>6i&-4  
} \s@7pM=(  
84f~.45  
@s % !R  
public void run() Q1 5h \!u  
{ it)!-[:bm  
//获得文件长度 )KbzgmLr  
//分割文件 3$n O@rOS  
//实例FileSplitterFetch Z1Pdnc7S[  
//启动FileSplitterFetch线程 *p.70,5,  
//等待子线程返回 JW2~ G!@  
try{ ]w5j?h"b  
if(bFirst) 17ol %3 M  
{ VSDG_:!K  
nFileLength = getFileSize(); JBMJR  
if(nFileLength == -1) "V3f"J?  
{ wgcKeTD9  
System.err.println("File Length is not known!"); &57s//PrX  
} ]b&O#D9  
else if(nFileLength == -2) ;56mkP  
{ 0ME.O +  
System.err.println("File is not access!"); 2S@aG%-)  
} gw_]Y^U  
else I=c}6  
{ f2]O5rX p  
for(int i=0;i<nStartPos.length;i++) TD^w|U.  
{ py%_XL=w,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ;NPbEPL[5  
}  )k6O  
for(int i=0;i<nEndPos.length-1;i++) Z~6PrM-M  
{ Hq!|(  
nEndPos = nStartPos[i+1]; j1i<.,0g  
} &Ndq ^!e  
nEndPos[nEndPos.length-1] = nFileLength; d3&l!DoX  
} `&/~%>  
} Z9p`78kYyh  
*Hed^[sO  
( SiwO.TZ  
//启动子线程 4<<T#oW.:G  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;vp[J&=  
for(int i=0;i<nStartPos.length;i++) q'CtfmI`r=  
{ yr[HuwU  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3aERfIJyE  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %Q.|qyq  
nStartPos,nEndPos,i); )mh,F# "L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jr3FDd]  
fileSplitterFetch.start(); b75en{aDi*  
} D"ecwx{%;C  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @mm~i~~KA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lCxPR'C|  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IRY/0v  
nEndPos = " + nFileLength);  .H7xG'$  
// fileSplitterFetch[nPos.length-1].start(); F&)(G\  
P+(q38f[  
jImw_Q  
//等待子线程结束 N}X7g0>hV  
//int count = 0; %WO4uOi:@  
//是否结束while循环 pUm|e5  
boolean breakWhile = false; ]]!&>tOlI  
!Jk|ha~r  
Wo, "$Z6B  
while(!bStop) K;P<c,9X/  
{ N*6lyFcg  
write_nPos(); -XMWN$Ah  
Utility.sleep(500); ^w+)A;?W  
breakWhile = true; DUlvlQW  
=BVBCh  
+H6cZ,  
for(int i=0;i<nStartPos.length;i++) $I4:g.gKpG  
{ /~}<[6ZGCY  
if(!fileSplitterFetch.bDownOver) mj|TWDcj+  
{ rw%1>]os  
breakWhile = false; Mx_O'D  
break; JzZ@Z8%a;  
} {-.ZFUZmT  
} y25L`b  
if(breakWhile) c7f11N!v>b  
break; ]Z=O+7(r  
! ~3zp L  
xt=ELzu$  
//count++; V 2/?1  
//if(count>4) lL6W:Fq@(  
// siteStop(); Y9ipy_@_?  
} XyrQJ}WR|  
i=aK ?^+  
2NvbQ 3c5  
System.err.println("文件下载结束!"); W*.6'u)9  
} rlP?Uh  
catch(Exception e){e.printStackTrace ();} ty-erdsP  
} (GB*+@  
:7 OhplI  
DWmViuZmL  
//获得文件长度 "C'T>^qw*  
public long getFileSize() u3])_oj=  
{ D{G~7P\.  
int nFileLength = -1; {"n=t`E)3  
try{ &KP JB"0L  
URL url = new URL(siteInfoBean.getSSiteURL()); -_+,HyJP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O]%Vh l  
httpConnection.setRequestProperty("User-Agent","NetFox"); q&d5V~q  
R~!md  
-YJ4-]Z  
int responseCode=httpConnection.getResponseCode(); b1Fd]4H3P  
if(responseCode>=400) MGfIA?u  
{ _h0hl]rf  
processErrorCode(responseCode); Z;[f,Oj  
return -2; //-2 represent access is error 3JXKp k?   
} Kp?j\67S  
K3-Cuku  
U2HAIV8  
String sHeader; .u\xA7X  
Q@5v> `  
/& wA$h  
for(int i=1;;i++) /@feY?glc  
{ L6n<h  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5rlZ'>I.  
//Utility.log(in.readLine()); s8|F e_  
sHeader=httpConnection.getHeaderFieldKey(i); t;L7H E@Y  
if(sHeader!=null) d[$YTw  
{ .g52p+Z#  
if(sHeader.equals("Content-Length")) ]JvZ{fA%*  
{ d8% sGH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qfa[KD)!aB  
break; o7 1f<&1  
} 5KRI}f  
} H`EsFKw\%  
else $Fik]TbQp  
break; ,Uu#41ZOKL  
} (8jQdbZU  
} q~G@S2=}0}  
catch(IOException e){e.printStackTrace ();} ew 4pAav  
catch(Exception e){e.printStackTrace ();} 8G?OZ47k#  
*7G5\[gI$  
5~\GAjf  
Utility.log(nFileLength); {bMOT*X=A  
WNWtQ2]  
yYn7y1B  
return nFileLength; tq&CJvJ4  
} 9f_Qs4  
Ae|bAyAK  
;b;Bl:%?  
//保存下载信息(文件指针位置) vd#BT$d?  
private void write_nPos() #Pe|}!)u  
{ I.hy"y2&  
try{ }CB9H$FkCY  
output = new DataOutputStream(new FileOutputStream(tmpFile)); |P(8T'  
output.writeInt(nStartPos.length); k btQ  
for(int i=0;i<nStartPos.length;i++) )F65sV{  
{ B'!I{LC  
// output.writeLong(nPos); gib'f@i;  
output.writeLong(fileSplitterFetch.nStartPos); S/)yi  
output.writeLong(fileSplitterFetch.nEndPos); /{ FSG!  
} 35Cm>X  
output.close(); akV-|v_  
} JHCXUT-r{  
catch(IOException e){e.printStackTrace ();} dz=pL$C  
catch(Exception e){e.printStackTrace ();} -i*]Sgese  
} /j;HM[  
MoMxKmI  
WI\jm&H r  
//读取保存的下载信息(文件指针位置) $[{YE[a  
private void read_nPos() 7Kn}KO!Y8  
{ 4'GosQ85  
try{ 6![}Jvu>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QM4O|x[   
int nCount = input.readInt(); @nxpcHj  
nStartPos = new long[nCount]; )POU58$  
nEndPos = new long[nCount]; !]2`dp\!  
for(int i=0;i<nStartPos.length;i++) 9Z lfY1=  
{ $3yn-'o'A  
nStartPos = input.readLong(); eh}I?:(a?  
nEndPos = input.readLong(); cs7K^D;.V  
} c%5Suu( J6  
input.close(); /[,0,B9!3  
} p%ZAVd*|#V  
catch(IOException e){e.printStackTrace ();} N.dcQQ_iS  
catch(Exception e){e.printStackTrace ();} RLR\*dL1  
} !T RU  
E5 uk<e_  
:@K~>^+U  
private void processErrorCode(int nErrorCode) ?eOw8Rom  
{ Fb<fQIa  
System.err.println("Error Code : " + nErrorCode); gRg8D{  
} z(Q 5?+P  
mae@L  
\.Z /  
//停止文件下载 n7(/ml+Q_  
public void siteStop() ?#Y1E~N  
{ u -A_l<K  
bStop = true; wrAcVR  
for(int i=0;i<nStartPos.length;i++) bD<hzOa  
fileSplitterFetch.splitterStop(); P`OZoI$bV  
K?eY<L  
L)9uBdF  
} ((T6z$:hA  
} 9a0|iy  
//负责部分文件的抓取 UaXWHCm`  
**FileSplitterFetch.java X{tfF!+iy  
*/ CM4#Nn=i~  
package NetFox; - sL4tMP  
!;M5.Y1j&"  
wH]Y1 m  
import java.io.*; tqzr +  
import java.net.*; ~vB dq Yj  
@|d+T"f  
PXo^SHJ+gt  
public class FileSplitterFetch extends Thread { k@^T<Ci  
)}i|)^J  
:aWC6"ik-W  
String sURL; //File URL $\q}A:  
long nStartPos; //File Snippet Start Position l,:> B-FV  
long nEndPos; //File Snippet End Position 5~{s-Ms  
int nThreadID; //Thread's ID _NN5e|t  
boolean bDownOver = false; //Downing is over F~wqt7*  
boolean bStop = false; //Stop identical Pv3qN{265  
FileAccessI fileAccessI = null; //File Access interface Lv7$@|"H9  
{)PgN  
} bm ^`QY  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .wf$]oQQ  
{ 'pC51}[A{^  
this.sURL = sURL; C(&3L[  
this.nStartPos = nStart;  wkKSL  
this.nEndPos = nEnd; 51Q~/  
nThreadID = id; x bD]EC  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g]jCR*]  
} g<^-[w4/  
G!E1N(%o  
,$bK)|pGV  
public void run() u+qj_Ej  
{ SY$%)(c8kL  
while(nStartPos < nEndPos && !bStop) %OJq(}  
{ )M_|r2dDq3  
%,f(jQfg_  
S#N4!"  
try{ Ah_0o_Di  
URL url = new URL(sURL); epG!V#I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lN'b"N  
httpConnection.setRequestProperty("User-Agent","NetFox"); X][=(l!;w7  
String sProperty = "bytes="+nStartPos+"-"; }TRVCF1  
httpConnection.setRequestProperty("RANGE",sProperty); +l;AL5h  
Utility.log(sProperty); b] ~  
?<U">8cP  
S^_F0</U,  
InputStream input = httpConnection.getInputStream(); @waY+sqt=  
//logResponseHead(httpConnection); d'[]  
iyP0;$  
kerBy\^  
byte[] b = new byte[1024]; 7uq^TO>9f  
int nRead; Ny G?^  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #]z_pp:  
{ @6%o0p9zz  
nStartPos += fileAccessI.write(b,0,nRead); M?QX'fia  
//if(nThreadID == 1) gXe`G( w  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l(d3N4iz  
} #A=ER[[  
Yz ? 8n  
zR5KC!xc  
Utility.log("Thread " + nThreadID + " is over!"); TV~S#yg+H  
bDownOver = true; 91M5F$  
//nPos = fileAccessI.write (b,0,nRead); ]}L tf,9  
} s3y"y_u  
catch(Exception e){e.printStackTrace ();} S@cKo&^  
} (lt{$0   
} |Q$9I#rv  
Wd?=RO`a  
s^HI%mdf  
//打印回应的头信息 ]K|td)1X  
public void logResponseHead(HttpURLConnection con) qqSFy>`P  
{ OPC8fX5.  
for(int i=1;;i++) xM**n3SZ`  
{ gmN$}Gy}  
String header=con.getHeaderFieldKey(i); liPaT  
if(header!=null) +^ `n- m  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JzmX~|=Xi  
Utility.log(header+" : "+con.getHeaderField(header)); <\oD4EE_  
else X9;51JV  
break; ;nAI;Qw L  
} > *soc!#Y  
} [Nu py,v  
nJY3 1(p  
G(gZL%M6  
public void splitterStop() ;@H:+R+(  
{ c{[lT2yxU  
bStop = true; UeU`U  
} f47dB_{5f.  
R7/ET"  
g9gi7.'0  
} remRm Y?  
T+41,  
$Z<x r  
/* @@H?w7y?&  
**FileAccess.java >J/8lS{#  
*//文件访问(定位,写) uMX\Y;N  
package NetFox; Y{9xF8#  
import java.io.*; <aQ5chf7  
#3_ @aq*  
G rI<w.9X  
public class FileAccessI implements Serializable{ wicW9^ik  
dZCnQIS  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v (=E R%  
RandomAccessFile oSavedFile; LvNulMEK  
long nPos; 75;g|+  
Nf%/)Tk  
mX[J15  
public FileAccessI() throws IOException {_UOS8j7  
{ e*M-y C  
this("",0); ,O_iSohS  
} aUq 2$lw1  
Dq+S'x~>  
Rw)=<XV)6  
public FileAccessI(String sName,long nPos) throws IOException (e4 #9  
{ Y|ErVf4  
oSavedFile = new RandomAccessFile(sName,"rw"); QypUBf  
this.nPos = nPos; #'BPW<Ob  
oSavedFile.seek(nPos); 8wMwS6s:  
} <YvW /x  
a"^rOiXR{  
wY3| 5kbDj  
public synchronized int write(byte[] b,int nStart,int nLen) eu'S~c-l  
{  ^w_\D?  
int n = -1; =3EjD;2  
try{ 'oF XNO  
oSavedFile.write(b,nStart,nLen); Q096M 0m  
n = nLen; y7x*:xR[  
} 6N[X:F 3`,  
catch(IOException e) fWyXy%Qq  
{ Mk}*ze0%  
e.printStackTrace (); +asO4'r  
} !o\e/HGc!  
!,R=6b$E5  
RLfB]\w  
return n; >fzFNcO*  
} MqRJ:x  
kAq#cLprG  
}8'b}7!  
} 6[-[6%o#z  
KPA.5,ai  
0<+eN8od.  
/* u}89v1._Jn  
**SiteInfoBean.java b-RuUfUn0  
*/ ~~q>]4>  
package NetFox; }6gum  
I.it4~]H  
D9!$H!T _  
public class SiteInfoBean { ?hYWxWW  
J3$@: S'  
tGF3Hw^mS  
private String sSiteURL; //Site's URL tac\Ki?  
private String sFilePath; //Saved File's Path 6G{ Q@  
private String sFileName; //Saved File's Name $e:bDZ(hjj  
private int nSplitter; //Count of Splited Downloading File #I\" 'n5M  
}=|plz}  
zbjV>5  
public SiteInfoBean() nH B  
{//nSplitter的缺省值为5 Zgo%Jo  
//default value of nSplitter is 5 y-{?0mLq  
this("","","",5); } L _Zmi$  
} LCW}1H:Q  
Pbt7T Q  
#7@p  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -q\Rbb5M  
{ ^I) +u>fJ  
sSiteURL= sURL; U+zntB  
sFilePath = sPath; qfjUJ/  
sFileName = sName; $W%-Mm  
this.nSplitter = nSpiltter; D@kf^1G  
;=WwJ Np~  
'4CD }  
} KDb`g}1Q  
0 {  
1iqgVby  
public String getSSiteURL() y+KAL{AGK  
{ 'V &Tlw|  
return sSiteURL; :(@P *"j  
} )_Z^oH ]<  
hzT)5'_  
Wg20H23XW  
public void setSSiteURL(String value) '.C#"nY>1  
{ U uC-R)  
sSiteURL = value; h1l%\3ZH  
} &x;n^W;#  
>P]gjYN  
@C^wV  
public String getSFilePath() g@T}h[  
{ #2Iag' 4T  
return sFilePath; SPXv i0Jg  
} e\O-5hp7  
*+nw%gZG  
g> ~+M  
public void setSFilePath(String value) $/|vbe,  
{ g>k?03;  
sFilePath = value; w*&vH/D  
} Y B,c=Wx  
kW1w;}n$  
@_7rd  
public String getSFileName() n$v4$_qS  
{ WA0D#yuJ/  
return sFileName; pWq+`|l$  
} o\]U;#YD  
'.M4yif \g  
43]y]/do  
public void setSFileName(String value) v5@M 34  
{ b%vIaP|]B  
sFileName = value; Sc/$ 2gSG  
} <XQwu*_\  
(m6V)y  
[cco/=c  
public int getNSplitter() 2pU'&8  
{ ?~4x/d%  
return nSplitter; v/=\(  
} >^GV #z  
U^7bj  
<i]0EE}%  
public void setNSplitter(int nCount) s]|tKQGl,  
{ 79D~Mau#  
nSplitter = nCount; t 7o4 aBl"  
} 1U/RMN3`  
} )RT?/NW  
([}08OW@  
9[;da  
/* }WaZ+Mdg\  
**Utility.java "qd|!:bE  
*/ 9x|`XAB  
package NetFox; C#^y{q  
jT}={[9b  
MtaGv#mJ  
public class Utility { ^m&I^ \  
:8hI3]9  
miu?X!  
public Utility() }z$_!)/i  
{ dR;N3KwY  
#o7)eKeQ  
E}v8Q~A(  
} } Z FoCMM  
|w54!f6w_  
//线程睡眠 /t`\b [  
public static void sleep(int nSecond) 6ulx0$[  
{ 2[HPU M2>  
try{ GK!@|Kk8q7  
Thread.sleep(nSecond); T^(W _S  
} oBo*<6  
catch(Exception e) {it}\[3  
{ tx~,7TMS/  
e.printStackTrace (); ~!qnKM>[  
} jC4>%!{m  
} u~ipB*Zf  
=gD)j&~}_  
//日志 X%j`rQk`  
public static void log(String sMsg) {H)hoAenA  
{ {+=hYB|&  
System.err.println(sMsg); P.C?/7$7Z+  
} R54ae:8  
I;%1xdPt  
\X _}\_c,d  
public static void log(int sMsg) _uLpU4# ?  
{ BDvkY  
System.err.println(sMsg); ,]7ouH$H}  
} HI 1T  
} t(6]j#5   
}DS%?6}Sy  
GIH{tr1:<  
/* wT\BA'VQ  
**TestMethod.java 't&1y6Uu  
*/ \t&! &R#  
package NetFox; TB* t^ E  
G}g;<,g~  
6XF Ufi+  
public class TestMethod { ]vvA]e  
Sx'oa$J  
Eu'E;*- f  
public TestMethod() S.~L[iLc  
{ ///xx/weblogic60b2_win.exe L"vrX  
try{ _ia&|#n  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O- QT+]  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8wvHg_U6W  
SiteFileFetch fileFetch = new SiteFileFetch(bean); o>C,Db~L/  
fileFetch.start(); 2HmK['(  
} ch]Qz[d  
catch(Exception e){e.printStackTrace ();} T`":Q1n  
<O0tg[ub  
i0K 2#}=^  
} (ct1i>g  
os"R'GYmf  
Qe>_\-f  
public static void main(String[] args) VsL,t\67  
{ \-pwA j?  
new TestMethod(); L?+N:G  
} g;'S5w9S  
} H=C~h\me?  
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:
3+5=?,请输入中文答案:八 正确答案:八