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
  • 8089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
/* :MP*Xy\7&J  
**SiteFileFetch.java o"V+W  
*/ KB"N',kG  
package NetFox; 8\X-]Gh\^  
import java.io.*; M!/!*,~  
import java.net.*; qs%UJ0tR  
-O^R~Q_`w  
4 Aj<k  
public class SiteFileFetch extends Thread { S}b^_+UbP  
Ei7Oi!1  
q'Nafa&a)  
SiteInfoBean siteInfoBean = null; //文件信息Bean (KLhF  
long[] nStartPos; //开始位置 4;bc!> sfC  
long[] nEndPos; //结束位置 Z[9t?ePL  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 h"y~!NWn  
long nFileLength; //文件长度 l;SXR <EU  
boolean bFirst = true; //是否第一次取文件 s&4&\Aq}x#  
boolean bStop = false; //停止标志 :4r{t?ytXw  
File tmpFile; //文件下载的临时信息 <t&Qa~mA  
DataOutputStream output; //输出到文件的输出流 ]6 HR  
3L CT-rp  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) {4$aA*  
public SiteFileFetch(SiteInfoBean bean) throws IOException ``-pjD(t  
{  6oI/*`>  
siteInfoBean = bean; 8B(=Y;w  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); &P,uK+C4  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 4?fpk9c{2  
if(tmpFile.exists ()) 6)PnzeYW  
{ iR!]&Oh  
bFirst = false; o%,?v 9  
read_nPos(); 4wN5x[vp  
} zsLMROo3  
else e*y l_iW  
{ D/ VEl{ba-  
nStartPos = new long[bean.getNSplitter()]; *10qP?0H  
nEndPos = new long[bean.getNSplitter()]; ?iZM.$![  
} 6V"u ovN2  
I)kc[/^j$  
4H^ACw  
1% C EUE  
} ~Zn|(  
H#u N&^+H  
0CvGpM,  
public void run() WD_{bd)  
{ MGf*+!y,  
//获得文件长度 O')=]6CQ*  
//分割文件 ~"_!O+Pj  
//实例FileSplitterFetch +\*b?x  
//启动FileSplitterFetch线程 C23p1%#1  
//等待子线程返回 RU=\eD  
try{ !Eg2#a?  
if(bFirst) XDAP[V  
{ wwRPfr[  
nFileLength = getFileSize(); F!phTu  
if(nFileLength == -1) "TP~TjXfq  
{ &Z3%UOY  
System.err.println("File Length is not known!"); jhPbh5E  
} d >NO}MR  
else if(nFileLength == -2) V7}'g6X  
{ k ~Q 5Cs  
System.err.println("File is not access!"); P*B @it  
} lXF7)H&T  
else 8#HnV%|N  
{ /CH]'u^j  
for(int i=0;i<nStartPos.length;i++) +0)M1!gK  
{ (7N!Jvg9  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,(-V<>/*.|  
} z]SEPYq:  
for(int i=0;i<nEndPos.length-1;i++) :nR80]  
{ "G~!J\  
nEndPos = nStartPos[i+1]; NMfHrYHbh  
} J<0d"'  
nEndPos[nEndPos.length-1] = nFileLength; xJAQ'ANr  
} b !y  
} IU5T5p  
0%< hj  
+Adk1N8  
//启动子线程 G[JWG  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `)5WA{z  
for(int i=0;i<nStartPos.length;i++) X(eW+,H  
{ c-5AI{%bl6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l$pz:m]Id  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (sQXfeMz  
nStartPos,nEndPos,i); =+K?@;?  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S9r?= K  
fileSplitterFetch.start(); =Gu&0f  
} ?>U=bA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pDYJLh-C  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +or<(%o @  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .D ^~!A  
nEndPos = " + nFileLength); GS=E6  
// fileSplitterFetch[nPos.length-1].start(); = c Z24I  
qEXN} Pq<  
#) :.1Z?  
//等待子线程结束 #+p-  
//int count = 0; A.("jb@I  
//是否结束while循环 i0$*):b  
boolean breakWhile = false; >W8"Ar  
I/O/*^T  
tuIZYp8tIN  
while(!bStop) B~ i  
{ aQ $sn<-l  
write_nPos(); 65dMv*{  
Utility.sleep(500); KcpYHWCa.  
breakWhile = true; c QuL9Xo  
p*,T~(A6  
!hZ: \&V  
for(int i=0;i<nStartPos.length;i++) RG'76?z  
{ z2t+1 In,  
if(!fileSplitterFetch.bDownOver) 7`;f<QNo  
{ Pb>/b\&JS  
breakWhile = false;  |@'O3KA  
break; eGq7+  
} KzO"$+M  
} S}VS@KDO  
if(breakWhile) )Ln".Bu,  
break; hBpa"0F  
$'3xl2T  
p__wBUB  
//count++; f\dfKNm6  
//if(count>4) 7$lnCvm  
// siteStop(); B8T$<  
} Rv9jLH  
30uPDDvar  
6 Ln~b<I  
System.err.println("文件下载结束!"); \\<=J[R.M  
} iOURS  
catch(Exception e){e.printStackTrace ();} WM ?a1j  
} hk4t #Km  
( ~5 M{Xh  
kaekH*m~  
//获得文件长度 v}Ju2}IK  
public long getFileSize() 'v V7@@  
{ mvZ#FF1,J  
int nFileLength = -1; MHK|\Z&e7  
try{ `nl n@ ;  
URL url = new URL(siteInfoBean.getSSiteURL()); 6j<!W+~G  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gk%@& TB/  
httpConnection.setRequestProperty("User-Agent","NetFox"); g5@g_~ g  
b[<RcM{r}  
Df^F)\7!N?  
int responseCode=httpConnection.getResponseCode(); Fa )QDBz)  
if(responseCode>=400) MWh Y&I+  
{ @9B*V~ <  
processErrorCode(responseCode); VWE>w|'  
return -2; //-2 represent access is error ;Nj9,Va(t  
} lQ;BI~  
2aM7zP[Z  
'*b]$5*p  
String sHeader; Jo\P,-\(  
!=YKfzE  
_VK I@   
for(int i=1;;i++) A#=TR_@:  
{ Mu? |<#s  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t R|dnC4U  
//Utility.log(in.readLine()); 5 aA* ~\  
sHeader=httpConnection.getHeaderFieldKey(i); v4n< G-  
if(sHeader!=null) nMyl( kF[  
{ +P2oQ_Fk`9  
if(sHeader.equals("Content-Length")) !5o j~H  
{ e|\xF V=4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gA!@oiq@  
break; Wb-C0^dTn  
} pd|KIs%jl  
} Jay"  
else  yfZNL?2x  
break; "o&8\KSs  
} cs+3&T: ,*  
} eThaH0  
catch(IOException e){e.printStackTrace ();} $eYL|?P50h  
catch(Exception e){e.printStackTrace ();} KC6Cg?y^  
lvO6&sF1  
e7RgA1  
Utility.log(nFileLength); K*>%,mP$i  
VVas>/0qr  
5qb93E"C  
return nFileLength; {]T?)!V m  
} @Vre)OrN#  
0<uek  
Ek_5% n  
//保存下载信息(文件指针位置) hIJtu;}zU  
private void write_nPos() }5;4'l8  
{ >rCD5#DG  
try{ {o}U"b<+Ra  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )L:z r#  
output.writeInt(nStartPos.length); [IL*}M!  
for(int i=0;i<nStartPos.length;i++) 0[MYQl`  
{ Jb QK$[z"  
// output.writeLong(nPos); ZZY#.  
output.writeLong(fileSplitterFetch.nStartPos); K~TwyB-h  
output.writeLong(fileSplitterFetch.nEndPos); e&}W#  
} IfK~~XYG  
output.close(); =-h^j  
} Y[{:?i~9,  
catch(IOException e){e.printStackTrace ();} Ie.*x'b?y  
catch(Exception e){e.printStackTrace ();} AW]\n;f  
} D.K""*ula  
\MP~}t}c  
W [ l  
//读取保存的下载信息(文件指针位置) .XJ'2yKof  
private void read_nPos() 7n7Xyb  
{ XX8HSw!w  
try{ vMTf^V  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q(bOar5  
int nCount = input.readInt(); {R}F4k  
nStartPos = new long[nCount]; DB/~Z  
nEndPos = new long[nCount]; mmTpF]t ?`  
for(int i=0;i<nStartPos.length;i++) 7Sx|n}a-3  
{ z'YWomfZm  
nStartPos = input.readLong(); ,;$OaJFT  
nEndPos = input.readLong(); p F-Lz<V  
} xXe3E&  
input.close(); V8^la'_j  
} ~ :ASv>m  
catch(IOException e){e.printStackTrace ();} >JpBX+]5m  
catch(Exception e){e.printStackTrace ();} im<bo Mv  
} v:t;Uk^Y  
%{u@{uG0'3  
nip6|dN  
private void processErrorCode(int nErrorCode) |oY{TQ<<d  
{ 'f5 8Jwql  
System.err.println("Error Code : " + nErrorCode); fiGTI}=P  
} UA>=# $  
u]yy%@U1  
PkvW6,lS  
//停止文件下载 ;4nY{)bD  
public void siteStop() >y3FU1w5d  
{ >q"dLZ  
bStop = true; `i.BB jx`  
for(int i=0;i<nStartPos.length;i++) ,mHME~  
fileSplitterFetch.splitterStop(); n' ~ ==2  
9@ k8$@  
# T=iS(i  
} yHeL&H  
} 'C]w3Rh'  
//负责部分文件的抓取 xl&@g)Jj  
**FileSplitterFetch.java EXDDUqZ5\  
*/ L&pR#  
package NetFox; CX|W$b)%  
1oQw)X  
/<rvaR  
import java.io.*; J"`VA_[  
import java.net.*; @<\oM]jX  
bMO^}qR`  
gv*b`cl  
public class FileSplitterFetch extends Thread { OoB|Eh|),  
eZ'8JU]  
L'+bVP{L  
String sURL; //File URL ] ZV[}7I.  
long nStartPos; //File Snippet Start Position [`n_> p!  
long nEndPos; //File Snippet End Position =U]9>  
int nThreadID; //Thread's ID OX_y"]utU  
boolean bDownOver = false; //Downing is over +_5*4>MC  
boolean bStop = false; //Stop identical LV:L0D7y  
FileAccessI fileAccessI = null; //File Access interface R(1:I@<?E  
hA7=:LG  
sscbf  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5YY5t^T  
{ :""HyjY!  
this.sURL = sURL; 'RjEdLrI  
this.nStartPos = nStart; Lq(=0U\"P  
this.nEndPos = nEnd; wvv+~K9jq  
nThreadID = id; Z"`w>c.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )lG}B U.  
} UG2+Y']  
yE:y[k0E  
|E8sw a  
public void run() 2j s/>L0  
{ Ac:`xk<  
while(nStartPos < nEndPos && !bStop) UqK.b}s  
{ ]s\r3I]  
z !K2UTX  
!0;AFv`\  
try{ Y{} ub]i  
URL url = new URL(sURL); fn}E1w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~+Wx\:TT  
httpConnection.setRequestProperty("User-Agent","NetFox"); vjEDd`jYZ  
String sProperty = "bytes="+nStartPos+"-"; K~L&Z?~|E  
httpConnection.setRequestProperty("RANGE",sProperty); Z RVt2  
Utility.log(sProperty); NI?O  
K#R]of~/  
\{h_i FU!  
InputStream input = httpConnection.getInputStream(); Zbczbnj  
//logResponseHead(httpConnection); &g :(I  
kWr1>})'  
U0&myj 8L  
byte[] b = new byte[1024]; _Ewh:IM-  
int nRead; %' DO FiU  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R"cQyG4  
{ iOiF kka  
nStartPos += fileAccessI.write(b,0,nRead); 6n9/`D!  
//if(nThreadID == 1) kV'zA F v  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *zdD4 I=  
} "f91YX_)  
2S8;=x}/  
<cTX;&0=  
Utility.log("Thread " + nThreadID + " is over!"); 9D3W_eIc  
bDownOver = true; wd`p>  
//nPos = fileAccessI.write (b,0,nRead); AiHU*dp6  
} %]P{)*y-?  
catch(Exception e){e.printStackTrace ();} [2@:jLth=  
} IdmP!(u  
} ![z2]L+TB  
R27'00(Z0  
`l|Oj$  
//打印回应的头信息 oCT,v0+4O  
public void logResponseHead(HttpURLConnection con) e$9a9twl  
{ +`d92Tz  
for(int i=1;;i++) |f_'(-v`E  
{ c.>f,vtcn  
String header=con.getHeaderFieldKey(i); >Na.C(DZ  
if(header!=null) &M|rRd~*  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /stvNIEa  
Utility.log(header+" : "+con.getHeaderField(header)); -Q? i16pM  
else [n"eD4)K|  
break; Xt$qjtVM  
} 6wp1jN  
} ?mNB:-Q  
3zsp 6kV  
JD *HG]  
public void splitterStop() h0F=5| B  
{ { j_-iF  
bStop = true; ]xRR/S4  
} i!YfR]"}  
6 IvAs-%W  
-6)nQNj|  
} rWr'+v?  
`l45T~`]$  
c/ Pql!h+  
/* 0moAmfc  
**FileAccess.java ;1&"]N%  
*//文件访问(定位,写) "L.k m  
package NetFox; =-^A;AO(  
import java.io.*; &$s:h5HoX  
1uw1(iL+  
i$kB6B#==  
public class FileAccessI implements Serializable{ JV_`E_!  
<y7{bk~i  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dNR /|  
RandomAccessFile oSavedFile; 0er| QC  
long nPos; #`y[75<n  
h[dJNawL  
k (AE%eA  
public FileAccessI() throws IOException Rxdj}xy  
{ O.jm{x!m  
this("",0); Z"c-Ly{vEj  
} "6C a{n1hk  
;BuMzG:tmZ  
A\?t^T  
public FileAccessI(String sName,long nPos) throws IOException ]#NfH-T  
{ _N;@jq\q  
oSavedFile = new RandomAccessFile(sName,"rw"); ou0TKE9 _  
this.nPos = nPos; |ufT)+:  
oSavedFile.seek(nPos); 4Pr^>m  
} z#G\D5yX[*  
,q%X`F rc  
RF*>U a  
public synchronized int write(byte[] b,int nStart,int nLen) n ^9?(a4u  
{ 8^EWD3N`  
int n = -1; `XF[A8@h  
try{ !84Lvg0&  
oSavedFile.write(b,nStart,nLen); uKzx >\}?1  
n = nLen; W'"hjQ_  
} >3&  
catch(IOException e)  }c||$  
{ l`~$cK!  
e.printStackTrace (); <Z t]V`-  
} V=fu[#<@Ig  
Q}Ah{H0C  
Ur 1k3  
return n; ()j)}F#Z`  
} Fep@VkN  
o#"yFP1  
#IGcQY  
} 8\E=p+C  
AHr^G'  
IZdWEbN1  
/*  DEu0Z  
**SiteInfoBean.java $'}|/D  
*/ /Gnt.%y&  
package NetFox; tYMr  
!!A(A^s  
|H=5Am  
public class SiteInfoBean { [qxpu{  
&OFVqm^  
/(||9\;  
private String sSiteURL; //Site's URL ^xk4HF   
private String sFilePath; //Saved File's Path ;s~xS*(C  
private String sFileName; //Saved File's Name Y,mo}X<>  
private int nSplitter; //Count of Splited Downloading File .z$UNB(!M  
<NDV 5P  
%1cxZxGT  
public SiteInfoBean() o9ys$vXt*  
{//nSplitter的缺省值为5 #2\M(5d  
//default value of nSplitter is 5 Y&M{7  
this("","","",5); x$Wtkb0<  
} &Odrq#o?R  
xP9R d/xa|  
IecD41%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8WLh7[  
{ I_Z?'M  
sSiteURL= sURL; g<F+Ldgj  
sFilePath = sPath; I|bX;l  
sFileName = sName; Gn6\n'r0  
this.nSplitter = nSpiltter; .@r{Tq,%q8  
[GM!@6U  
 ZJ)>gV  
} 1IgTJ" \  
CNj |vYj  
F*z>B >{)  
public String getSSiteURL() {a>JQW5=  
{ UC`sq-n  
return sSiteURL; ?3LV$S)U  
} |]:6IuslJ  
q 7W7sw  
V[^AV"V  
public void setSSiteURL(String value) 1mh7fZgn  
{ k,OxGG  
sSiteURL = value; 7"eIZ  
} kVeY} 8  
%;_EWs/z8  
i5WO)9Us  
public String getSFilePath() dqU)(T=C  
{ -NzOX"V]3  
return sFilePath; ^755 LW  
} @VND}{j  
1*#hIuoj'  
mWoN\Rwj  
public void setSFilePath(String value) )abH//Pps.  
{ &a >UVs?=  
sFilePath = value; yWN'va1+$  
} 5^qs>k[mN  
BD.l5 ~:  
:hB6-CZkqN  
public String getSFileName() A[Ce3m  
{ .ezko\nU  
return sFileName; b V_<5PHP  
} rCGKE`H  
v!S(T];)  
F_}y[Yn^  
public void setSFileName(String value) `Lw Z(M-hI  
{ %0u5d$bq  
sFileName = value; bLg gh]Fh  
} Mu" vj*F  
X)TZ  S  
8BY`~TZO$q  
public int getNSplitter() E9.1~ )  
{ djdSD  
return nSplitter; D+BflI~9mP  
} j9%vw.3b  
H?=[9?1wI5  
L]X Lv9J0  
public void setNSplitter(int nCount) ][\ uH|  
{ 6!U~dt#a  
nSplitter = nCount; E_z,%aD[  
} ! OVi\v 'm  
} 4/x.qoj  
wqE2n  
=xH>,-8}  
/* zyK11  
**Utility.java #)T'a  
*/ <qoPBm])  
package NetFox; c!$~_?]  
1JGww]JZo  
{v3@g[:|  
public class Utility { MzW!iG  
~vZ1.y4  
b3=XWzK5  
public Utility() v9D[| 4  
{ c)QOgXv  
.p~.S&)  
X-"0Zc  
} -zH-9N*c  
TU| 0I  
//线程睡眠 Pj^Ccd'>=  
public static void sleep(int nSecond) > LU !Z  
{ xLbF9ASim  
try{ CS xB)-  
Thread.sleep(nSecond); MA mjoH  
} V2 }.X+u&<  
catch(Exception e) SwH#=hg  
{ H[/^&1P  
e.printStackTrace (); 2ZxZ2?.uJ  
} DY87NS*HF  
} B an" H~  
NA$ODK -  
//日志 <U /r U9O  
public static void log(String sMsg) rqM_#[Y?  
{ ${U H!n{  
System.err.println(sMsg); k~1{|HxrE  
} )B^T7{  
K!G/iz9SB  
Kku@!lv  
public static void log(int sMsg) _ =(v? 2:?  
{ K+U0YMRmz  
System.err.println(sMsg); cn ;2&  
} Fz$^CMw5K  
} W$R@Klz  
{f>e~o  
]"vpCL  
/* nlx~yUXL4  
**TestMethod.java d:n .Vp  
*/ I\6^]pi,  
package NetFox; B{Lzgw u;  
L<N=,~  
$I3}% '`+  
public class TestMethod { }Do$oyAV$G  
VC NQ}h[D  
3_Re>i  
public TestMethod() 'p,54<e  
{ ///xx/weblogic60b2_win.exe `9VRT`e  
try{ 3{- 8n/4 k  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5);  9\R+g5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4V5h1/JPm  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Nu%MXu+  
fileFetch.start(); _ Av_jw`m  
} 4p(\2?B%f  
catch(Exception e){e.printStackTrace ();} u,Cf4H*xS  
rge/qUr/^  
:LR>U;2  
} )G|'PXI@,  
(DKQHL;  
iC<qWq|S_m  
public static void main(String[] args)  !*-|s}e  
{ J po(O>\P  
new TestMethod(); NFb<fD[C  
} , *Z!Bd8  
} &;%LTF@I,  
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