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
  • 7904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
/* {ersXQ:  
**SiteFileFetch.java MJX m7<(  
*/ ?I 1@:?Qi  
package NetFox; }Gz"og*8  
import java.io.*; /HDX[R   
import java.net.*; pp[? k}@  
 m|"MJP  
oci-[CI,  
public class SiteFileFetch extends Thread { 9HEc=,D|  
95wV+ q*  
n5]<|>U vx  
SiteInfoBean siteInfoBean = null; //文件信息Bean LZ ID|-  
long[] nStartPos; //开始位置 >)pwmIn<  
long[] nEndPos; //结束位置 Gz@%UIv  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ._tv$Gd@k  
long nFileLength; //文件长度 dYV)lMJ*  
boolean bFirst = true; //是否第一次取文件 +uwjZN'9a  
boolean bStop = false; //停止标志  "rjJ"u 1  
File tmpFile; //文件下载的临时信息 -RH ?FJ  
DataOutputStream output; //输出到文件的输出流 =C\S6bF%  
\^-3)*r  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ?\#4`9  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4'rk3nT8  
{ Y!*,G]7  
siteInfoBean = bean; O.K8$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); vPwDV_zk  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0 q3<RX>M%  
if(tmpFile.exists ()) b8v$*{  
{ u%[*;@;9+  
bFirst = false; jv|IV  
read_nPos(); kx UGd)S  
} rjR  
else {Ue6DK %  
{ puqH%m+u  
nStartPos = new long[bean.getNSplitter()]; >LU*F|F]B  
nEndPos = new long[bean.getNSplitter()]; [bOy, ^@4  
} 4 |5ekwk  
kh,M'XbTo  
Iwn@%?7  
MB |(,{S  
} Ol%*3To  
t583Q/1@  
! 6 $>|  
public void run() O: BP35z_F  
{ [7s5Vt|  
//获得文件长度 'b^:"\t'Rh  
//分割文件 t=e0z^2i+  
//实例FileSplitterFetch 2iG(v._x  
//启动FileSplitterFetch线程 >Ia(g0  
//等待子线程返回 wFd*6%  
try{ -=sxbs.aA  
if(bFirst) Z.mV fy%  
{ <m6I)}K  
nFileLength = getFileSize(); p$%h!.~99T  
if(nFileLength == -1) z~Pmh%b  
{ fVN}7PH7+  
System.err.println("File Length is not known!"); *nC,= 2  
} yED^/=\)}  
else if(nFileLength == -2) oF6MV&q/  
{ :<v$vER,&  
System.err.println("File is not access!"); Yptsq@s  
} =Ffq =<  
else m{5$4v,[  
{ AP7W)S  
for(int i=0;i<nStartPos.length;i++) eJA{]^Zf  
{ Iw:("A&~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); a?MtY EK2  
} 1G;Ns] u  
for(int i=0;i<nEndPos.length-1;i++) Iq=B]oE  
{ Tz-cN  
nEndPos = nStartPos[i+1]; k$ M4NF~$  
} V<pqc&f .  
nEndPos[nEndPos.length-1] = nFileLength; ~.lH)  
} ;X6y.1N~  
} H7= z%Y9y  
|K-lg rA  
rQm  
//启动子线程 7 tpZE+OX  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D` X6'PP  
for(int i=0;i<nStartPos.length;i++) fYjsSUnf  
{ B3t>M) 9  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >[: 2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k f!/9  
nStartPos,nEndPos,i); -c?wEqa~2  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zn!  
fileSplitterFetch.start(); $:N "*  
} \KXEw2S  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z+W&C@Uw  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5O W(] y|  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", TkoXzG8yE<  
nEndPos = " + nFileLength); 05 Q8`  
// fileSplitterFetch[nPos.length-1].start(); JW [\"`x!  
gVJ#LJ  
U3K<@r  
//等待子线程结束 :+Ax3  
//int count = 0; I<K/d  
//是否结束while循环 [5*-V^m2  
boolean breakWhile = false; si_ HN{  
D>e\OfTR:  
}t3FAy(%  
while(!bStop) SvP\JQ<c  
{ U hhmG+  
write_nPos(); z8 ;#H tr  
Utility.sleep(500); cloSJmUlQ  
breakWhile = true; F'$S!K58  
u=}bq{  
H8]^f=  
for(int i=0;i<nStartPos.length;i++) <?{}Bo0xG  
{ AE4~M`6D  
if(!fileSplitterFetch.bDownOver) -yQ\3wli`  
{ L(n/uQ :  
breakWhile = false; %=4ak]As  
break; >[fVl 8G_0  
} kF,\bM  
} `s> =Sn&UP  
if(breakWhile) ]z=Vc#+!  
break; i;hc]fYb=K  
UnWGMo?JEi  
k-pEBh OH  
//count++; B%J%TR_  
//if(count>4) km\ld&d]$  
// siteStop(); :sVHY2x  
} mHEf-6|C`  
%^5@z1d,  
j"IM,=  
System.err.println("文件下载结束!"); %L13Jsw  
} %FyygTb;S  
catch(Exception e){e.printStackTrace ();} )ClMw!ZrU  
} U\Ar*b)/T  
6=,#9C9  
^'[@M'`~L  
//获得文件长度 4iv]N 4  
public long getFileSize() Hg9.<|+yo  
{ [+l  
int nFileLength = -1; _rMT{q3  
try{ %]<RRH.w  
URL url = new URL(siteInfoBean.getSSiteURL()); }PFt  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -H4+ur JJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); Sc/`=h]T  
iTLW<wG  
'8l yj&  
int responseCode=httpConnection.getResponseCode(); nQ642i%RQ  
if(responseCode>=400) [X }@Ct6  
{ ~y)bYG!G  
processErrorCode(responseCode); %K^gUd>,R  
return -2; //-2 represent access is error \o B'  
} 8jjFC9Cbn0  
Vm~qk  
SH vaV[C  
String sHeader; z+k=|RMau  
$7UoL,N>  
6QII&Fg  
for(int i=1;;i++) +mc [S  
{ hD_5~d  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `*NO_ K  
//Utility.log(in.readLine()); Y$`eg|$  
sHeader=httpConnection.getHeaderFieldKey(i); q]eFd6  
if(sHeader!=null) VT% KN`l  
{ #v4LoNm  
if(sHeader.equals("Content-Length")) PFS;/   
{ X>Al:?`}N  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hIuMHq7h  
break; S9 G+#[.|  
} BTTLy^  
} p^1zIC>F  
else +Qh[sGDdY  
break; bmOqeUgB  
} N0Efw$u  
} , 3X: )  
catch(IOException e){e.printStackTrace ();} J7BFk ?=  
catch(Exception e){e.printStackTrace ();} /gz:zThf{  
ba uA}3  
@Od^k#  
Utility.log(nFileLength); A8pj~I/*-  
KD% TxK  
FR x6c  
return nFileLength; l|YT[LR7  
} 5@P%iBA4(3  
VF)uu[ f9  
Hm%g_Mt  
//保存下载信息(文件指针位置) gmh5 %2M  
private void write_nPos() mxQR4"]jY  
{ 6M ^IwE  
try{ (1CJw:  
output = new DataOutputStream(new FileOutputStream(tmpFile)); egm)a   
output.writeInt(nStartPos.length); 55.;+B5L *  
for(int i=0;i<nStartPos.length;i++) RMoJz6 ^>  
{ g"wxC@IR  
// output.writeLong(nPos); zZ%DtxUoU.  
output.writeLong(fileSplitterFetch.nStartPos); 2-++i:, g  
output.writeLong(fileSplitterFetch.nEndPos); 4j> fI)FUW  
} ^ [k0k(_  
output.close(); b"``D ?  
} V vu(`9u]  
catch(IOException e){e.printStackTrace ();} ?O??cjiA@  
catch(Exception e){e.printStackTrace ();} gv#4#]  
} `)32&\  
x?"#gK`3;  
e,HMwD  
//读取保存的下载信息(文件指针位置) \m4T3fy  
private void read_nPos() ,CciTXf  
{  1,,|MW  
try{ lWWP03er!  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MIq"Wy|Zs  
int nCount = input.readInt(); hSB?@I4s<\  
nStartPos = new long[nCount]; -gS"pE^1  
nEndPos = new long[nCount]; k=[pm5ZvT~  
for(int i=0;i<nStartPos.length;i++) )RN<GW'  
{ ;+ azeW ^  
nStartPos = input.readLong(); XphE loL  
nEndPos = input.readLong(); xRum*}|4  
} F8<"AI  
input.close(); 5t\HJ`C1Z  
} =E(#YCx  
catch(IOException e){e.printStackTrace ();}  ?CP2AK  
catch(Exception e){e.printStackTrace ();} ;o0#(xVz  
} ?]#OM_,8  
.2W"w)$nuq  
7]E m ,  
private void processErrorCode(int nErrorCode) +m)q%I>  
{ 1@>$ Gcc  
System.err.println("Error Code : " + nErrorCode); Y9Z]i$qS&k  
} l30Y8t~d  
:@eHX&  
|A\a4f 'G  
//停止文件下载 =Mj 0:rW  
public void siteStop() kJ{+M]pW  
{ k GHQ`h  
bStop = true; *nC(-(r:J`  
for(int i=0;i<nStartPos.length;i++) os4{0Mxu  
fileSplitterFetch.splitterStop(); wi_'iv  
:"Y*<=x#2  
DY\J[l<<  
} -]srp;=i  
} IgIYguQ   
//负责部分文件的抓取 !4(zp;WY^  
**FileSplitterFetch.java CrC =A=e  
*/ v+G=E2Lhv  
package NetFox; QA3/   
r)^vO+3u  
S<`I Jpkv  
import java.io.*; W3H+.E  
import java.net.*; 5T@aCC@$h  
[sF(#Y:I  
aNxAZMg  
public class FileSplitterFetch extends Thread { <\ `$Jx#  
pav'1d%  
PPkx4S_>  
String sURL; //File URL rG}\Zjn{  
long nStartPos; //File Snippet Start Position Hnk:K9u.B:  
long nEndPos; //File Snippet End Position CVNj- &vj  
int nThreadID; //Thread's ID y5r4+2B  
boolean bDownOver = false; //Downing is over 7 aV%=_  
boolean bStop = false; //Stop identical A@hppaP!  
FileAccessI fileAccessI = null; //File Access interface 8[vc?+>&  
nKa$1RMO  
":a\z(*t  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $+p?Y)h .  
{ ryB}b1`D  
this.sURL = sURL; AN!s{7V3  
this.nStartPos = nStart; 21hv%CF\9  
this.nEndPos = nEnd; \K`L3*cBKK  
nThreadID = id; >/[GTqi  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I/Jb!R ~  
} ~5FW [_  
g0R~&AN!g  
h/?l4iR*  
public void run() wE+${B03  
{ (hiyNMC  
while(nStartPos < nEndPos && !bStop) '5&s=M_  
{ ^nbnbU4'  
T,aW8|  
y@0E[/O  
try{ /1Ue?)g  
URL url = new URL(sURL); Cj~'Lhmv'T  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FEVEp  
httpConnection.setRequestProperty("User-Agent","NetFox"); }gJ(DbnV  
String sProperty = "bytes="+nStartPos+"-"; (L^]Lk x)  
httpConnection.setRequestProperty("RANGE",sProperty); Ym3\pRFiD  
Utility.log(sProperty); Fu!RhsW5j  
th;{V%:LW  
/p8dZ+X  
InputStream input = httpConnection.getInputStream(); 0 $,SF3K  
//logResponseHead(httpConnection); w!fE;H8w6  
ZYC<Wb)I  
8F._9U-EN  
byte[] b = new byte[1024]; ;q*e=[_DF  
int nRead; On?p 9^9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8F'x=lIO  
{ %i5M77#Z  
nStartPos += fileAccessI.write(b,0,nRead); ."9];)2rx  
//if(nThreadID == 1) ~]QHk?[wc  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y&V@^ "`  
} yU9DSY\m{  
-3Hy*1A.  
E{|W(z,  
Utility.log("Thread " + nThreadID + " is over!"); 1fpQLaT  
bDownOver = true; ZzSz%z_sE  
//nPos = fileAccessI.write (b,0,nRead); Ft&]7dT{W  
} 'Iw NTM  
catch(Exception e){e.printStackTrace ();} C#Na&m  
} [Al&  
} !qWH`[:  
"vOwd.(?N  
Fvbh\m ~  
//打印回应的头信息 [k/@E+;  
public void logResponseHead(HttpURLConnection con) R=QZgpR  
{ {0WHn.,2Y  
for(int i=1;;i++) :51/29}  
{ ++`0rY%  
String header=con.getHeaderFieldKey(i); bcE._9@@  
if(header!=null) OG>}M$ Ora  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }f6HYU  
Utility.log(header+" : "+con.getHeaderField(header)); ZZzMO6US0  
else ~ v|>xqWV  
break; \D*KGd]M0  
} D=-SO +  
} :% ,:"  
huh6t !  
lww!-(<ww  
public void splitterStop() 7o# I,d~  
{ w"Gm;B4  
bStop = true; Y[}>CYO  
} -"' j7t:  
)<h*eS{  
[\v}Ul  
} i@"@9n~  
<7/R,\Wg~  
EyJJ0  
/* su{poQ}K  
**FileAccess.java @#T|Y&  
*//文件访问(定位,写) jCOIuw  
package NetFox; < $lCkSx<Q  
import java.io.*; l rlgz[  
<Tzrj1"Q3  
v&DI`xn~  
public class FileAccessI implements Serializable{ .WA-&b_  
`T@i.'X  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  mHdA2  
RandomAccessFile oSavedFile; {Aw#?#GPW  
long nPos; . qO@Q=  
Z'`<5A%;  
1"MhGNynB>  
public FileAccessI() throws IOException O_oPh] x)  
{ 4&<oFW\r  
this("",0); IA8f*]?  
} il4^zj82  
UZ\u;/}  
5Dm.K?l;  
public FileAccessI(String sName,long nPos) throws IOException #L=x%8B  
{ y-'$(x  
oSavedFile = new RandomAccessFile(sName,"rw"); @vC4[:"pD}  
this.nPos = nPos; %(3|R@G.  
oSavedFile.seek(nPos); 1H? u Qy  
} ? uzRhC_)!  
dk[!V1x4\  
i1ixi\P{0  
public synchronized int write(byte[] b,int nStart,int nLen) 2b}t,&bv?  
{ a!6{:8Zi0  
int n = -1; !JHL\M>A5  
try{ V\ZGd+?  
oSavedFile.write(b,nStart,nLen); u^@f&BIG]:  
n = nLen; W,V:R  
} !"?#6-,Xn  
catch(IOException e) eBZXI)pPh  
{ @'#,D!U  
e.printStackTrace (); \FQRNj?'_  
} ZQ4p(6a   
!`Fxa4i>  
|7'df&CA  
return n; %<\vGqsM  
} Qf~vZtJ+J  
yr)G]K[/  
1-8mFIK  
} I:R[;TB?y  
yZ0-wI  
5kc/Y/4o  
/* }^ApJS(FQ  
**SiteInfoBean.java dN$0OS`s[  
*/ ne>pOK<vZ  
package NetFox; Go5J%&E9  
Q- cFtu-w  
%f&/E"M  
public class SiteInfoBean { -o ^7r@6  
l.67++_  
8zZvht*  
private String sSiteURL; //Site's URL du<tGsy  
private String sFilePath; //Saved File's Path MU`1LHg  
private String sFileName; //Saved File's Name k KaE=H-x  
private int nSplitter; //Count of Splited Downloading File |U:k,YH  
hi_NOx  
1T"`v tR  
public SiteInfoBean() Ot4 Z{mA  
{//nSplitter的缺省值为5 AHD=<7Rs  
//default value of nSplitter is 5 "M<8UE\n  
this("","","",5); Eq%}  
} /Wi[OT14  
I,E?h?6Y  
DwM)r7<Ex  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4X!/hI=jq  
{ @CpfP;*{w`  
sSiteURL= sURL; UE8kpa)cQ  
sFilePath = sPath; .T}Wdn g  
sFileName = sName; Y4J3-wK5  
this.nSplitter = nSpiltter; _zR+i]9   
${<%" hR$  
]Z>}6!  
} sfpZc7  
mUNn%E:7@{  
'F/~o1\.  
public String getSSiteURL() MU($|hwiL  
{ &agWaf1%a  
return sSiteURL; i[O& )N,c  
} g?c xp +  
aHV;N#Lx3  
Jf{*PgP  
public void setSSiteURL(String value) '*Z1tDFS  
{ ?j'7l=94A  
sSiteURL = value; 6]&OrS[  
} BnX0G1|#  
6O7'!@@  
9>= ;FY  
public String getSFilePath() j5(Z_dm'  
{ |hKDvH  
return sFilePath; =T3 <gGM  
} B?OFe'*  
7LfAaj  
N+9VYH"*  
public void setSFilePath(String value) u0}vWkn\4  
{ J-[,KME_^  
sFilePath = value; 2A']y D  
} /Y/UM3/  
=%BSKSG.  
d8DV[{^  
public String getSFileName() jSJqE _1  
{ \Q {m9fE  
return sFileName; %p Ynnfr  
} tl[Uw[  
n"h `5p5'  
N&.H|5  
public void setSFileName(String value) nyX2|m&  
{ cF\;_0u  
sFileName = value; +UCG0D  
} <!&[4-;fU  
J9..P&c\  
^dI424  
public int getNSplitter() aKJwofD  
{ {IjF+@I  
return nSplitter; hE &xE;  
} =R^%(Py  
D+#E -8  
H!@kO]?n  
public void setNSplitter(int nCount) # ncRb  
{ x/%aM1"X^  
nSplitter = nCount; ;RH;OE,A  
} ?'IP4z;y  
} R$EW4]j  
mJ<=n?{Z  
N(O9&L*4fm  
/* |e=,oV"  
**Utility.java pXtl 6K%  
*/ seba9 y  
package NetFox; c|f<u{'  
W=ig.-  
C2.HMgL  
public class Utility { M+-*QyCFK  
36.Z0Z1'F>  
Dxtp2wu%t  
public Utility() oph}5Krd)  
{ !d'GE`w T  
f<GhkDPm>?  
1}"++Z73P  
} E!;SL|lj.  
Qo>b*Ku;  
//线程睡眠 pD(j'[  
public static void sleep(int nSecond) bkRLC_/d  
{ |Yx~;q:  
try{ ~cWAl,(B<F  
Thread.sleep(nSecond); 1v#%Ei$6`t  
} \TIT:1  
catch(Exception e) ^0Zf,40  
{ ag;Q F  
e.printStackTrace (); a,Sw4yJ!Q  
} 85>05 ?  
} Y y5h"r  
'-QwssE  
//日志 8."]//V  
public static void log(String sMsg) ,y1PbA0m  
{ +\x,HsUc"  
System.err.println(sMsg); v/@^Q1 G/:  
} 4Xgg%@C  
7Sf bx~48  
-M~8{buxv  
public static void log(int sMsg) ~3^ 8>d/  
{ WJ$bf(X*  
System.err.println(sMsg); svsqg{9z  
} ^/)^7\@  
} dW)B1iUo!  
<qtr   
B#exHf8  
/* ~Uu4=  
**TestMethod.java ,%6P0#-  
*/ &]g}u5J!=  
package NetFox; :uP,f<=)K  
i=ea ?eT`  
YA''2Ii  
public class TestMethod { \?w2a$?6w  
iyA'#bE-  
>i_ 2OV  
public TestMethod() &@G:G(  
{ ///xx/weblogic60b2_win.exe v;BV@E0}x  
try{ 6q*9[<8  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W~6EEyD%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UGD2  
SiteFileFetch fileFetch = new SiteFileFetch(bean); @>u]4Jn  
fileFetch.start(); YO#M/%^j  
} Q8C_9r/:N>  
catch(Exception e){e.printStackTrace ();} c*(bO3 b  
&?W0mW(  
IW>T}@ |  
} -1 FPkp  
pN!}UqfI-  
#~#R-   
public static void main(String[] args) vY4\59]P  
{ wi;Br[d  
new TestMethod(); nePfu G]Q  
} Vdtry @Q  
} ?QsQnQ  
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:
3+5=?,请输入中文答案:八 正确答案:八