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
  • 10025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
/* lvs  XL  
**SiteFileFetch.java 7L{1S v  
*/ oL<#9)+2*  
package NetFox; )ZG;.j  
import java.io.*; 3o<d= @`r  
import java.net.*; )dXa:h0RZ  
_gvFs %J  
Jh26!%<Bl  
public class SiteFileFetch extends Thread { $*yYmF  
|Wh3a#  
{ i5?R,a)  
SiteInfoBean siteInfoBean = null; //文件信息Bean sVLvnX,  
long[] nStartPos; //开始位置 bz4Gzp'6k  
long[] nEndPos; //结束位置 '0<d9OlJ}  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 t&r.Kf9Z\  
long nFileLength; //文件长度 7aG.?Ca%  
boolean bFirst = true; //是否第一次取文件 1|bXIY.J*  
boolean bStop = false; //停止标志 Q#bW"},^k  
File tmpFile; //文件下载的临时信息 ,T/Gv;wa2  
DataOutputStream output; //输出到文件的输出流 ]P4WfV d  
&OMlW _FHR  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) V>@[\N[  
public SiteFileFetch(SiteInfoBean bean) throws IOException U&!TA(Yr  
{ j#NyNv(jE1  
siteInfoBean = bean; @CMI$}!{V  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =~#mF<z5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); j{@O %fv=  
if(tmpFile.exists ()) 4ot<Uw5  
{ %( )d$.F  
bFirst = false; %go2tv:|W  
read_nPos(); )H8_.]|  
} ;Rrh$Ag  
else P}bIp+  
{ ,/;Ae w;  
nStartPos = new long[bean.getNSplitter()]; 1'kO{Ge*p:  
nEndPos = new long[bean.getNSplitter()]; =o@;K~-  
} 7- B.<$uC  
<I+kB^Er  
dbp\tWaW  
:6n#y-9^1  
} o+A7hBM^  
mw @Pl\=  
+C( -f  
public void run() H4$qM_N  
{ 'o AmA=  
//获得文件长度 GABZsdFZ!  
//分割文件 xL}i9ozZ  
//实例FileSplitterFetch w^yb`\$  
//启动FileSplitterFetch线程 l45/$G7  
//等待子线程返回 LUOjaX  
try{ JGs: RD'  
if(bFirst) --yF%tRMP  
{ h\s/rZg=r  
nFileLength = getFileSize(); 2g.lb&3W  
if(nFileLength == -1) _&<n'fK[  
{ 5mH [|_  
System.err.println("File Length is not known!"); _^NX`<&  
} > p`,  
else if(nFileLength == -2) mH o#"tc  
{ .<x6U*)\O  
System.err.println("File is not access!"); C{exvLQ  
} S?J!.(  
else 0w?da~  
{ M4^G3c<  
for(int i=0;i<nStartPos.length;i++) q<3nAE$?=  
{ CM6% g f3  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 144Y.  
} AdX))xgl  
for(int i=0;i<nEndPos.length-1;i++) tOwn M1 :(  
{ !_QI<=X  
nEndPos = nStartPos[i+1]; f|[7LIdh-  
} Sj+H{xJi  
nEndPos[nEndPos.length-1] = nFileLength; g4K+AK  
} 'aSsyD!?<  
} [xS7ae  
s~M4. 06P  
+^.Yt0}  
//启动子线程 u mYsO.8  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]so/AdT9hA  
for(int i=0;i<nStartPos.length;i++) m`yvZ4K!  
{ >m%_`68  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y>o:5':;'  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n,N->t$i  
nStartPos,nEndPos,i); ,d"T2Hy  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &<&tdShI  
fileSplitterFetch.start(); jqUVERbc  
} i~@gI5[k+  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^e:z ul{;]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }:m#}s  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l6M?[  
nEndPos = " + nFileLength); ,=/9Ld2w9  
// fileSplitterFetch[nPos.length-1].start(); ,Py\Cp=Dw  
Sd+5Uf `  
qv!(In>u  
//等待子线程结束 K #3^GB3P  
//int count = 0; :1'  
//是否结束while循环 L+t / E`  
boolean breakWhile = false; ]U?nYppV  
T(!1\TB  
*zrT;j G  
while(!bStop) m&)/>'W   
{ rH}|~  
write_nPos(); $LP(\T([  
Utility.sleep(500); _i =*0Q  
breakWhile = true; Z{8%Cln  
* #yF`_p  
K\xz|Gq  
for(int i=0;i<nStartPos.length;i++) V@'Xj .ze  
{ l@`k:?  
if(!fileSplitterFetch.bDownOver) di\.*7l?  
{ }7PJr/IuF  
breakWhile = false; ;,y_^-h;  
break; 1+%UZK= K  
} .k#PrT1C  
} 0'sZ7f<e7  
if(breakWhile) dXyMRGR Uq  
break; 2&hv6Y1  
kZ9Gl!g  
x{H+fq,M  
//count++; 5i br1zs  
//if(count>4) Yy~x`P'g!  
// siteStop(); e$L C  
} 9Po>laT 5  
8mX!mYO3c  
+3,7 Apj  
System.err.println("文件下载结束!"); Z$z-Hx@%  
} vJE=H9E  
catch(Exception e){e.printStackTrace ();} \VPw3  
} [Rj4= qq=  
|W@ ~mrO  
*q}yfa35eR  
//获得文件长度 ydWr&E5  
public long getFileSize() GRc)3 2,  
{ L15)+^4n  
int nFileLength = -1; s}zR@ !`  
try{ :3F[!y3b  
URL url = new URL(siteInfoBean.getSSiteURL()); ^EIuGz1@0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0fc;H}B*  
httpConnection.setRequestProperty("User-Agent","NetFox"); \Z.r Pq  
CvIuH=,  
f]*;O+8$LN  
int responseCode=httpConnection.getResponseCode(); enk`I$Xx  
if(responseCode>=400) ch# )XomN  
{ 3MQHoxX  
processErrorCode(responseCode); WUS%4LL(  
return -2; //-2 represent access is error _'p/8K5)=  
} =CzGI|pb  
:k9T`Aa]  
|AvPg  
String sHeader; .7.G}z1  
yp~z-aRa  
(-<hx~  
for(int i=1;;i++) '`8 ^P  
{ o0Teect=  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gj|5"'g%  
//Utility.log(in.readLine()); B4 bB`r  
sHeader=httpConnection.getHeaderFieldKey(i); (XK,g;RoEn  
if(sHeader!=null) w,hm_aDq  
{ GwO`@-}E  
if(sHeader.equals("Content-Length")) .1(_7!m@  
{ `yR/M"u6T  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bAlty}U  
break; \7\sx:!$  
} rDl/R^w"  
} ll__A|JQ  
else B9l~Y/3|  
break; <ppdy,j:  
} auI`'O`/  
} s<*+=aIfu  
catch(IOException e){e.printStackTrace ();} e;v7!X  
catch(Exception e){e.printStackTrace ();} WOPIF~1v  
, S^y>  
#-%D(=&I  
Utility.log(nFileLength); Q``1^E'  
OcB&6!1u  
;$tdn?|  
return nFileLength; qFVZhBC  
} j6s j2D  
1<:5b%^c  
&wQ<sVQ0$  
//保存下载信息(文件指针位置) V 2Xv)  
private void write_nPos() Dx\~#$S!=  
{ f0eQq;D$K  
try{ ,t_&tbf3  
output = new DataOutputStream(new FileOutputStream(tmpFile)); tOXyle~C  
output.writeInt(nStartPos.length); Ew4D'; &;  
for(int i=0;i<nStartPos.length;i++) 9z?c0W5x  
{ rvx2{1}I  
// output.writeLong(nPos); `;Ui6{|  
output.writeLong(fileSplitterFetch.nStartPos); !bzWgD7j  
output.writeLong(fileSplitterFetch.nEndPos); =nHkFi@D=t  
} ZXLAX9|  
output.close(); 6Takx%U  
} F=&,=r' Q8  
catch(IOException e){e.printStackTrace ();} _)@G,E33f@  
catch(Exception e){e.printStackTrace ();} pZ $>Hh#  
} N?3p,2  
i`YZ;L L  
2V 8 "jc  
//读取保存的下载信息(文件指针位置) e O~p"d-|  
private void read_nPos() `pv  
{ `D3q!e  
try{ M*'8$|Z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;\"5)S  
int nCount = input.readInt(); 5%wA"_  
nStartPos = new long[nCount]; 9t`yv@.>N  
nEndPos = new long[nCount]; ,&Zp^  
for(int i=0;i<nStartPos.length;i++) =ZS Yg K  
{ zvN7aG  
nStartPos = input.readLong(); `]]m$  
nEndPos = input.readLong(); _G`Q2hf"5  
} 2cu2S"r  
input.close(); u;%~P 9O  
} ;=0-B&+v  
catch(IOException e){e.printStackTrace ();} QlVj#Jv;~  
catch(Exception e){e.printStackTrace ();} -7oIphJ=\  
} 4iSN.nxIZ  
/0`Eux\  
lhQMR(w^  
private void processErrorCode(int nErrorCode) CVY-U|xFY  
{ ^69(V LK  
System.err.println("Error Code : " + nErrorCode); U4Zx1ieCKH  
} >q')%j  
%X}D(_  
EAh|$~X  
//停止文件下载 lX.1B&T9Lr  
public void siteStop() +-x+c: IxA  
{ ZCK#=:ln  
bStop = true; rD6NUS  
for(int i=0;i<nStartPos.length;i++) !9qw  
fileSplitterFetch.splitterStop(); f% 8n?f3;u  
Z3<lJk\Y  
P;7[5HFF  
} H[R6 ?H@$F  
} hQ)?LPUB  
//负责部分文件的抓取 W`[7|8(6!  
**FileSplitterFetch.java amQiH!}8R  
*/ 'mv|6Y  
package NetFox; }If,O  
$/u.F;  
6QHUBm2  
import java.io.*; M"-53|#:w\  
import java.net.*; #p{8  
?t;,Nk`jx  
"SKv'*\b  
public class FileSplitterFetch extends Thread { !!6@r|.  
x wfdJ(&  
9e;{o,r@  
String sURL; //File URL |+-b#Sa9  
long nStartPos; //File Snippet Start Position Nog{w  
long nEndPos; //File Snippet End Position JBV 06T_4o  
int nThreadID; //Thread's ID 3"HEXJMc  
boolean bDownOver = false; //Downing is over # b3 14  
boolean bStop = false; //Stop identical C:!&g~{cKi  
FileAccessI fileAccessI = null; //File Access interface fX LsLh+~D  
B|>eKI  
I]#x0?D  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QVb{+`.7  
{ BL0xSNE**  
this.sURL = sURL; x {R j2~KC  
this.nStartPos = nStart; ? _[ q{i{  
this.nEndPos = nEnd; H_iQR9Ak7  
nThreadID = id; s2tNQtq 0W  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HS.eK#:N  
} m9'bDyyK  
^MWp{E  
* P12d  
public void run() rv~OfL  
{ r-hb]!t  
while(nStartPos < nEndPos && !bStop) nS!m1&DeD  
{ >)`*:_{  
KrTlzbw&p\  
vQ5rhRG)E  
try{ e{Mkwi+j  
URL url = new URL(sURL); PywUPsJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [ 7{cf`C  
httpConnection.setRequestProperty("User-Agent","NetFox"); <UW-fI)X  
String sProperty = "bytes="+nStartPos+"-"; n2opy8J#!  
httpConnection.setRequestProperty("RANGE",sProperty); tB0f+ wC  
Utility.log(sProperty); SphP@J<ONW  
}dq)d.c  
Q2gz\N  
InputStream input = httpConnection.getInputStream(); qz-lQ  
//logResponseHead(httpConnection); pW<l9W  
EP{ji"/7[  
AB.ZmR9|  
byte[] b = new byte[1024]; BS?rKtdm(  
int nRead; 7U)w\A;~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gp\o|igT  
{ %pxHGO=)E  
nStartPos += fileAccessI.write(b,0,nRead); %8KbVjn  
//if(nThreadID == 1) aqP"Y9l  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s8*Q@0  
} aO *][;0  
#%/0a  
'V4B{n7 h  
Utility.log("Thread " + nThreadID + " is over!"); qwuA[QkPi  
bDownOver = true; @i>4k  
//nPos = fileAccessI.write (b,0,nRead); KpKZiUQm  
} 1?y QjW,  
catch(Exception e){e.printStackTrace ();} AHplvksb  
} _10I0Z0  
} |Mnc0Fgvy,  
8$ _8Yva"e  
_.GHtu/I  
//打印回应的头信息 +qa^K%K  
public void logResponseHead(HttpURLConnection con) !$0ozDmD  
{ e$-Y>Dd  
for(int i=1;;i++) \`?4PQ  
{ |zp}u(N  
String header=con.getHeaderFieldKey(i); @(m?j1!M  
if(header!=null) ZY)&Fam}  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )%I62<N,z  
Utility.log(header+" : "+con.getHeaderField(header)); 1[(/{CClB  
else \2 [  
break; qD(dAU  
} KhNE_. Z  
} {G-y7y+E  
iB*1Yy0DC  
tIW~Ng  
public void splitterStop() j[$+hh3:  
{ RAoY`AWI  
bStop = true; q:P44`Aq  
} }ho6  
q!) nSD  
A{wSO./3  
} 5eX+9niY  
7;ddzxR4  
u/HNXJ7M`9  
/* tf{o=X.)  
**FileAccess.java <)$JA  
*//文件访问(定位,写) q} p (p( N  
package NetFox; z4s{a(Tsd  
import java.io.*; 26-K:"  
bSk)GZyH\d  
x3=SMN|a  
public class FileAccessI implements Serializable{ 8^qLGUxz  
Dp;6CGYl?  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kO' NT:  
RandomAccessFile oSavedFile; =BgQ Ss/^c  
long nPos; 0?,%B?A8O  
BA`K,#Ft7  
QzD8 jk#  
public FileAccessI() throws IOException +`~kt4W  
{ 6F?U:N#<  
this("",0); j7=x&)qbx  
} x|A{|oFC  
6iJ\7  
'n7Ld6%1  
public FileAccessI(String sName,long nPos) throws IOException 7HEUmKb"  
{ -h#9sl->  
oSavedFile = new RandomAccessFile(sName,"rw"); lm(k[]@  
this.nPos = nPos; \']_y\  
oSavedFile.seek(nPos); >?^_JE C6  
} Qr]`flQ8  
=.6JvX<d1*  
e~Z>C>J  
public synchronized int write(byte[] b,int nStart,int nLen) cy( WD#^  
{ Y~-P9   
int n = -1; ck#MpQ!An  
try{ ),4c b  
oSavedFile.write(b,nStart,nLen); h$a% PaVf  
n = nLen; !^(?C@TQ  
} S0p[Kt  
catch(IOException e) /\UFJ  
{ ;+R  
e.printStackTrace (); 7Ezy-x2h  
} ,&rHBNS  
=LojRY  
>vc$3%L[$  
return n; qBcwM=R3P  
} 2sahb#e )  
.L))EB  
9\a;75a  
} W3 2]#M=  
>Ef{e6  
vFl06N2  
/* ~Jx0#+z9V  
**SiteInfoBean.java P^& =L&U  
*/ {|/y/xYgy'  
package NetFox; @hj5j;NHK  
0m&W: c  
{K>}eO:K  
public class SiteInfoBean { NmZowh$M  
NVq3h\[X  
Q*8=^[x  
private String sSiteURL; //Site's URL NaYr$`  
private String sFilePath; //Saved File's Path MXGz_Db4'  
private String sFileName; //Saved File's Name &WoS(^  
private int nSplitter; //Count of Splited Downloading File Ig"Qw vR  
S[I-Z_S  
pn-`QB:{h  
public SiteInfoBean() 8;1,saA_9  
{//nSplitter的缺省值为5 !t!\b9=  
//default value of nSplitter is 5 b[`fQv$G  
this("","","",5); 2mfKy9QxO  
} O}mz@- Z  
%<[U\TL`  
pF}WMt  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zJX _EO  
{ db0]D\  
sSiteURL= sURL; }q D0-  
sFilePath = sPath; T~- OC0  
sFileName = sName; TjLW<D(i>  
this.nSplitter = nSpiltter; Vs@H>97,G  
J0O wzO  
xty)*$C>  
} w4(g]9^Q  
I/ V`@*/+  
ylwh_&>2  
public String getSSiteURL() DRuG5|{I:  
{ YK6zN>M}E  
return sSiteURL; XX[CTh?O%  
} 7dtkylW  
s2t9+ZA+s  
hmM2c15T5  
public void setSSiteURL(String value) :~%{  
{ m9 D' yXZ  
sSiteURL = value; ]c~W$h+F  
} ,AEaW  
Auk#pO#  
d@e2+3<  
public String getSFilePath() 5!*@gn  
{ Z[?zaQ$  
return sFilePath; 1&#qq*{  
} $Z[W}7{pt#  
)H| cri~D  
c-q=Ct  
public void setSFilePath(String value) 8D6rShx =  
{ G"D=ozr  
sFilePath = value; l[u=_uaYl  
} _fE$KaP  
$, @,(M`i}  
{?hpW+1,#  
public String getSFileName() Ic')L*i7O  
{ 9L9qLF5 t  
return sFileName; g8L{xwx<  
} ((cRe6  
W}aCU~  
"`Mowp*  
public void setSFileName(String value) > xie+ ^  
{ tv'=xDCp  
sFileName = value; 83g$k 9lG.  
} s5 ($b  
$ n"*scyI  
wjc&S'[  
public int getNSplitter() w~wg[d  
{ "'v^X!"  
return nSplitter; T3,}CK#O   
} L. DD  
+\)a p  
cT(=pMt8>  
public void setNSplitter(int nCount) 2pmqP-pKd  
{ UWo*%&J  
nSplitter = nCount; 5VjO:>  
} $~)YI/b  
} W@FSQ8b>$m  
0AD8X+M{P  
,jq:%Y[KZ  
/* :b`ywSp`  
**Utility.java 5N(OW:M  
*/ xZ(ryE%  
package NetFox; fprP$MbI  
ae0t *;~  
(d>}Fp  
public class Utility { DVz_;m6)  
p-XO4Pc 6  
L25%KGg' o  
public Utility() )18C(V-x  
{ ToX--w4  
Jp"yb`w  
o1Nfn'!3/>  
} LDh,!5G-M  
}*?,&9/_)  
//线程睡眠 Fxv5kho  
public static void sleep(int nSecond) W[<ZI>mf  
{ nZ % %{#T7  
try{ bYBEh n  
Thread.sleep(nSecond); SZ1yy["  
} 6_g:2=6S  
catch(Exception e) X.+|o@G  
{ 5 BLAa1  
e.printStackTrace (); J#xZ.6)  
} y;<F|zIm  
} K$I`&M(  
XNJ3.w:R  
//日志 Z ygu/M 6  
public static void log(String sMsg) 6u>]-K5  
{ $i@I|y/  
System.err.println(sMsg); Y.kgJ #2  
} M;9s  
*Gul|Lp$<I  
]-;MY@  
public static void log(int sMsg) spT$}F2n  
{ >R}G  
System.err.println(sMsg); U^8S@#1Q  
} }#h`1 uV  
} #Q'#/\5  
`j8pgnY>5~  
Cy dV$!&mP  
/* + w/B3 b  
**TestMethod.java b/?)_pg  
*/ 2N{^V?:  
package NetFox; 4W#DLip9  
+{0v@6<(02  
>&ENrvaJ  
public class TestMethod { 0f#xyS 3  
?Wc+ J4  
[kf6bf@  
public TestMethod() +Fb+dU  
{ ///xx/weblogic60b2_win.exe RM;Uq >l  
try{ =0a z5td  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _L+j6N.h1  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E0AbVa.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); vXm'ARj  
fileFetch.start(); \/64Xv3L0  
} td7Of(k'  
catch(Exception e){e.printStackTrace ();} &0i$Y\g  
Fw:_O2  
e07u@_'^  
} >gDeuye  
pu5%$}dBE  
IhRdn1&  
public static void main(String[] args) zf>*\pZE  
{ ;;6$d{  
new TestMethod(); Lt ^*L% x  
} Gt)ij?~  
} udXzsY9Ng  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八