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
  • 9315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
/* 8 A%)m  
**SiteFileFetch.java ?"qU.}kGL  
*/ 6wnfAli.  
package NetFox; /:U\U_j  
import java.io.*; {CQA@p:Y}  
import java.net.*; lQ! 6n  
!u\X,.h  
Wv(VV[?/&  
public class SiteFileFetch extends Thread { YM1@B`yWE  
ZL1[Khr,s  
lXv{+ic  
SiteInfoBean siteInfoBean = null; //文件信息Bean /x$O6gi  
long[] nStartPos; //开始位置 D_@r_^}  
long[] nEndPos; //结束位置 q'K=Ly+  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 x8zUGvtQ  
long nFileLength; //文件长度 5<ery~q  
boolean bFirst = true; //是否第一次取文件 _4.`$n/Z  
boolean bStop = false; //停止标志 f>p;Jh{2fn  
File tmpFile; //文件下载的临时信息 =P0~=UP  
DataOutputStream output; //输出到文件的输出流 s)ZL`S?</  
mjB%"w!S  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ||qsoF5B]  
public SiteFileFetch(SiteInfoBean bean) throws IOException c(YNv4*X  
{ ,VJ0J!@  
siteInfoBean = bean; =$b^ X?x  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); RUO,tB|(_;  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6I_W4`<VeZ  
if(tmpFile.exists ()) (kb^=kw#0  
{ `;QpPSw+  
bFirst = false; ~p oy`h'  
read_nPos(); _Y}(v( (;  
} e[R364K  
else #XC\= pZX  
{ Zr oj-3-X~  
nStartPos = new long[bean.getNSplitter()]; qjUQ2d  
nEndPos = new long[bean.getNSplitter()]; + s1mm c  
} Z$HYXm  
nJ'O(Wh,)  
10}\7p8  
.rN 5A+By`  
} g-Z>1V  
;wTl#\|w0  
m./lrz  
public void run() |910xd`Z  
{ %4+r&  
//获得文件长度 FS`{3d2K +  
//分割文件 {T m-X`  
//实例FileSplitterFetch rf]]I#C7  
//启动FileSplitterFetch线程 `4w0 *;k;  
//等待子线程返回 #/5jWH7U  
try{ I^\YD9~=x  
if(bFirst) ] hL 1qS  
{ F!'b_ gmz  
nFileLength = getFileSize(); KQQR"[z&V  
if(nFileLength == -1) pS*vwYA  
{ HPr5mWs:  
System.err.println("File Length is not known!"); A*MlK"  
} [T~O%ly7x&  
else if(nFileLength == -2) 2x3&o|J  
{ <\2,7K{{+;  
System.err.println("File is not access!"); j"J2&Y2  
} Wx;9N  
else 0gfa7+Y  
{ +a"A svw2  
for(int i=0;i<nStartPos.length;i++) EiIbp4*e  
{ /g@.1z1w  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); OYy%aA}h  
} &``;1/J*W  
for(int i=0;i<nEndPos.length-1;i++) cKFzn+  
{ ?sp  
nEndPos = nStartPos[i+1]; *vUKh^="  
} 0(:"q!h  
nEndPos[nEndPos.length-1] = nFileLength; m{gt(n  
} TQ>kmHWf/  
} f}  eZX  
}|{yd03 +  
Uhb6{'+  
//启动子线程 QfT&y &  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YG"P:d;s  
for(int i=0;i<nStartPos.length;i++) pmIQD"  
{ FeLWQn/aV6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }T4"#'`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ##1[/D(  
nStartPos,nEndPos,i); r`B8Cik  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vk@u|6U'  
fileSplitterFetch.start(); WR gAc%  
} ,MuLu,$/  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OHM.xw*?.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &{/ `Q ,  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d!e$BiC  
nEndPos = " + nFileLength); .5KRi6  
// fileSplitterFetch[nPos.length-1].start(); "%-HZw%X  
|giK]Z  
C03ehjT<  
//等待子线程结束 @j5W4HU  
//int count = 0; VU}UK$JN  
//是否结束while循环 +Rxf~m(pV  
boolean breakWhile = false; x_bS-B)%Y:  
D3(|bSca  
JU/K\S2%,  
while(!bStop) $PHKI B(  
{ Y@_ i32,r  
write_nPos();  4\dc  
Utility.sleep(500); K (Z d-U  
breakWhile = true; 8O("o7~"  
HQ ^> ~  
.+|G`*1<i  
for(int i=0;i<nStartPos.length;i++) &6r".\; ^  
{ H_vOZ0  
if(!fileSplitterFetch.bDownOver) p\b:uy6#  
{ "xdXHuX  
breakWhile = false; >77 /e@  
break; [[oX$0Fp\!  
} WTSY:kvcCY  
} -Ufd+(   
if(breakWhile) <y(>z*T;  
break; (#X/sZQh  
X -w#E3  
3Ki`W!C  
//count++; i1\xZ<|0  
//if(count>4) |Tf}8e  
// siteStop(); Yf7n0Etd,  
} T"dX)~E;  
+:mj]`=  
Pm#B'N#*N|  
System.err.println("文件下载结束!"); W>bhSKV%  
} !+JSguy  
catch(Exception e){e.printStackTrace ();} %* vYX0W"  
} c^Rz?2x  
^md7ezXL  
(ZT*EFhb(  
//获得文件长度 ol:,02E&  
public long getFileSize() P\*-n"  
{ ?dC[VYC\^  
int nFileLength = -1; o T5?*3f  
try{ ,BOB &u  
URL url = new URL(siteInfoBean.getSSiteURL()); CZxQz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); no)Spo'  
httpConnection.setRequestProperty("User-Agent","NetFox"); c{V0]A9VF  
+\\*Iy'xK  
Apa)qRJd  
int responseCode=httpConnection.getResponseCode(); ()}O|JL:K  
if(responseCode>=400) ;)u}`4~L  
{ UVxE~801Y  
processErrorCode(responseCode); Ajs<a(,6  
return -2; //-2 represent access is error -TjYQ  
} eLL> ThMyW  
{KdC5 1"Nv  
4/~8zvz&3  
String sHeader; 2fFNJ  
Q^b_+M  
9Rb-QI  
for(int i=1;;i++) !M)!  
{ iG6 ^s62z7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^$`xUKp`pn  
//Utility.log(in.readLine()); ;!Ojb  
sHeader=httpConnection.getHeaderFieldKey(i); T,`'qZ>  
if(sHeader!=null) B#B$w_z  
{ J55K+  
if(sHeader.equals("Content-Length")) zTAt% w5  
{ Haaungb"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %*oz~,i  
break; E )09M%fe  
} F2AM/m^!q  
} {ylc 2 1  
else J,4]d u$  
break; 9K Ih}Q@P  
} pvDr&n9  
} NA]7qb%%<  
catch(IOException e){e.printStackTrace ();} [qIi_(%o  
catch(Exception e){e.printStackTrace ();} ;]i&AAbj  
V4l`Alr\L  
[WRs1$5  
Utility.log(nFileLength); DSizr4R  
*;,=x<  
)j',e $m  
return nFileLength; i>7f9D7  
} gTH1FR8$y  
1AjsAi,7;2  
l:z :tJ#(  
//保存下载信息(文件指针位置) C ])Q#!D|  
private void write_nPos() e ! 6SJ7xC  
{ dY;^JPT  
try{ `[jQn;  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $io-<Z#Q  
output.writeInt(nStartPos.length); TEh]-x`  
for(int i=0;i<nStartPos.length;i++) n AoGG0$5  
{ \&&kUpI  
// output.writeLong(nPos); {YcVeCq+N  
output.writeLong(fileSplitterFetch.nStartPos); x98LOO  
output.writeLong(fileSplitterFetch.nEndPos); ]^3_eHa^d  
} OcQ_PE5\  
output.close(); zb?wl fT  
} I{_St8  
catch(IOException e){e.printStackTrace ();} PxfeU2^{0  
catch(Exception e){e.printStackTrace ();} lqF{Y<l  
} o~NeS|a  
7B"J x^  
0`h[|FYV  
//读取保存的下载信息(文件指针位置) nbMH:UY,J  
private void read_nPos() Jk}L+X vv  
{ P qagep d  
try{  +h9U V  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _>dqz(8#  
int nCount = input.readInt(); >tr_Ypfv,c  
nStartPos = new long[nCount]; JAC W#'4hV  
nEndPos = new long[nCount]; ]n _-  
for(int i=0;i<nStartPos.length;i++) PUltn}M  
{ #Vs/1y`()  
nStartPos = input.readLong(); >BrxJw#M  
nEndPos = input.readLong(); E&{*{u4  
} `y P-,lA$  
input.close(); s|pb0  
} ~XsS00TL`G  
catch(IOException e){e.printStackTrace ();} Gqk"%irZ  
catch(Exception e){e.printStackTrace ();} HAf.LdnzS  
} a_waLH/  
}(a y(  
U"%k4]:A  
private void processErrorCode(int nErrorCode) pvI(hjMYPk  
{ SjtGU47$!  
System.err.println("Error Code : " + nErrorCode); Rb#Z'1D'G  
} {;n?c$r  
Ook3B  
9`4h"9dO  
//停止文件下载 >, 234ab=d  
public void siteStop() )@]-bPnv  
{ x3PeU_9  
bStop = true; :`:<JA3,  
for(int i=0;i<nStartPos.length;i++) R>/M>*C  
fileSplitterFetch.splitterStop(); g"(N_sv?  
7/PHg)&  
a}i{b2B  
} '8*gJ7]  
} $#]?\psf  
//负责部分文件的抓取 /nv1 .c)k  
**FileSplitterFetch.java reu[}k~  
*/ [O"i!AQ  
package NetFox; 2O<S ig=  
)P|%=laE8  
{)4Vv`n  
import java.io.*; F#X\}MvEU  
import java.net.*; K ANE"M   
.Z%7+[  
e&; c^Z  
public class FileSplitterFetch extends Thread { EOtrrfT&  
Pk8L- [&v  
u%XFFt5  
String sURL; //File URL @]3(l  
long nStartPos; //File Snippet Start Position *uA?}XEfi  
long nEndPos; //File Snippet End Position <e/O"6='Z  
int nThreadID; //Thread's ID 4fzq C)  
boolean bDownOver = false; //Downing is over xBgf)'W_Z  
boolean bStop = false; //Stop identical y^;qT_)#  
FileAccessI fileAccessI = null; //File Access interface T2Y`q'  
R&ou4Y:DG  
lmH!I )5  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7c %@2  
{ &sS k~:  
this.sURL = sURL; OUI}jJw+  
this.nStartPos = nStart; ry~3YYEMI0  
this.nEndPos = nEnd; LTzf&TZbx5  
nThreadID = id; ^ / f*5k  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DOhXb  
} !PUhdW  
F<V zVEx  
}{K)5k@  
public void run() Wv=L_E_  
{ Z]w_2- -  
while(nStartPos < nEndPos && !bStop) I=(O,*+PQ  
{ :6HMb^4  
)&_{m K  
Y] P}7GZ  
try{ -\UzL:9>  
URL url = new URL(sURL); yA%[ u.{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~@'|R%jJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); JSGUl4N  
String sProperty = "bytes="+nStartPos+"-"; De>pIN;B>  
httpConnection.setRequestProperty("RANGE",sProperty); N..9N$+(  
Utility.log(sProperty); ~RvU+D  
e% 5!  
l' "<  
InputStream input = httpConnection.getInputStream(); Nz!AR$  
//logResponseHead(httpConnection); _F@FcFG1Z*  
,x{5,K.yWq  
F6%rH$aS  
byte[] b = new byte[1024]; ;A- Ef  
int nRead; _^P>@ ^  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5+ fS$Q  
{ Cs]xs9  
nStartPos += fileAccessI.write(b,0,nRead); []dRDe;#  
//if(nThreadID == 1) QtN0|q{af  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3>L1}zyM]  
} L {B#x@9tQ  
L"}@>&6  
KJ9~"v  
Utility.log("Thread " + nThreadID + " is over!"); ?[m5|ty#  
bDownOver = true; S?Eg   
//nPos = fileAccessI.write (b,0,nRead); 8De `.!Gg  
} o,aI<5"  
catch(Exception e){e.printStackTrace ();} e;!<3b  
} NoKYHN^*w  
} i^QcW!X&  
=A!I-@]q<  
57[O)5u.+  
//打印回应的头信息 JRodYXjE  
public void logResponseHead(HttpURLConnection con) m|f|u3'z$  
{ \ [>Rt  
for(int i=1;;i++) {|rwIRe  
{ dDm<'30?*v  
String header=con.getHeaderFieldKey(i); YDmFR,047  
if(header!=null) 0hNc#x6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B"Fg`s+]U  
Utility.log(header+" : "+con.getHeaderField(header)); -C8awtbC  
else G 8NSBaZe  
break; X;6X K$"  
} _')KDy7  
} 97Q!Rot  
4e%SF|(Y'h  
%"KBX~3+Kj  
public void splitterStop() w^ DAu1  
{ ~&yaIuW<  
bStop = true; x1Si&0T0P<  
} ]h|GaHiE  
@NyCMe;]  
[n:R]|^a  
} E3gQ`+wNg?  
`mWg$e,  
9]7^/g*!  
/* A$5!]+  
**FileAccess.java -7pZRnv  
*//文件访问(定位,写) l[.pI];T  
package NetFox; !MGQ+bD6  
import java.io.*; Y.}n,y|J}  
"arbUX~d  
I`y}Ky<q  
public class FileAccessI implements Serializable{ FijzO  
] xH `  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SgY>$gP9S  
RandomAccessFile oSavedFile; JgxOxZS`@  
long nPos; IG bQ L  
J7l1-  
ZM)a4h,kcm  
public FileAccessI() throws IOException 0#yo\McZ  
{ Y)a 7osML  
this("",0); @|cas|U.r  
} bF}~9WEa  
`U;4O)`n  
-bs~{  
public FileAccessI(String sName,long nPos) throws IOException h\20  
{ M&>Z[o  
oSavedFile = new RandomAccessFile(sName,"rw"); |~Z+Xl a  
this.nPos = nPos; M"V?fn'  
oSavedFile.seek(nPos); UCq+F96j  
} w-\GrxlbX  
|9(uiWf  
a"ht\v}1  
public synchronized int write(byte[] b,int nStart,int nLen) gx9H=c>/  
{ dwmj*+  
int n = -1; M VsIyP  
try{ $I tehy  
oSavedFile.write(b,nStart,nLen); my*/MC^O  
n = nLen; k'S/nF A  
} &PGU%"rN  
catch(IOException e) g.,IQ4o  
{ ,7/N=mz  
e.printStackTrace (); M/#<=XhA  
} EmH2 Dbw  
yCm iW %L4  
W/&cnp\  
return n; p'_* >%4~  
} tt`b+NOH>  
] ^.#d  
jLZ~9FXF2  
} \a}%/_M\  
N]5-#  
!rwv~9I  
/* //AS44^IS  
**SiteInfoBean.java #5'9T:8  
*/ sYp@.?Tz  
package NetFox; ya|7hz{  
A3h[VnuG,  
3g} ]nj:N  
public class SiteInfoBean { :PjHsNp;^  
*%Q!22?6F  
oU{m\r  
private String sSiteURL; //Site's URL 2AU_<Hr6  
private String sFilePath; //Saved File's Path zs7K :OlkA  
private String sFileName; //Saved File's Name fpzC#  
private int nSplitter; //Count of Splited Downloading File vu1F  
(uRAK  
{HQ?  
public SiteInfoBean() NPKRX Li%  
{//nSplitter的缺省值为5 U?H!:?,C  
//default value of nSplitter is 5 _ea!psA0  
this("","","",5); CB6<Vng}C  
} k+%6 :r,r&  
e6]u5;B r  
72Ft?;R  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N0/DPZX7  
{ ?mrG^TV^+r  
sSiteURL= sURL; {6A3?q  
sFilePath = sPath; &s\w: 9In  
sFileName = sName; Lymy/9  
this.nSplitter = nSpiltter; Ga$+x++'*  
Xgc@cwd  
qifX7AXHr  
} -Vw,9VCF  
,GGr@})  
lS9rgq<n  
public String getSSiteURL() P b2exS(  
{ p]IF=~b  
return sSiteURL; i!jx jP  
} |WlWZ8]  
^qYJx  
!SEg4z  
public void setSSiteURL(String value) Svy bP&i|  
{ BEN=/ v  
sSiteURL = value; hcwKi  
} LbvnV~S  
G' Jsk4:c  
Al6)$8]e   
public String getSFilePath() oJ>]=^?k  
{ k)dLJ<EM  
return sFilePath; OZs^c2 W  
} t-i;  
KR%DpQ&{'  
@'s^  
public void setSFilePath(String value) -AJe\ J 2  
{ ^6oz3+  
sFilePath = value; "{j4?3f)  
} $#8dtF  
0vt?yD  
R/xeC [r  
public String getSFileName() MAQkk%6[g  
{ E"nIC,VZ  
return sFileName; `(.K|l}  
} PiP\T.XANa  
y2 yW91B,  
OT&J OTk\  
public void setSFileName(String value) hK&jo(V  
{ 9v8{JaI3  
sFileName = value; TE3A(N'  
} -y)ij``VY  
}RDGk+x7|  
oxha8CF]D  
public int getNSplitter() >7p?^*&7;  
{ u-$(TyDEl|  
return nSplitter; vzd1:'^t  
} $&I##od  
S{zi8Oc6  
:4;ZO~eq!  
public void setNSplitter(int nCount) F /IXqj  
{ B{PI&a9~s%  
nSplitter = nCount; M6[&od  
} {'NdN+_C  
} B#N(PvtE  
I>B-[QEC  
4U*J{''L  
/* Om,+59ua*  
**Utility.java !MOVv\@O  
*/ hjtkq .@  
package NetFox; #qtAFIm'  
a4Qr\"Qm  
]<V[H  
public class Utility { ~D PjTR  
yO; r]`j0  
Az8>^|@  
public Utility() NiQ`,Q$B  
{ 6-c3v  
}K!}6?17T  
p'M5]G  
} [#.E=s+&  
m-dyvW+  
//线程睡眠 AK]{^Hvz  
public static void sleep(int nSecond) ) wtVFG  
{ >7[. {Y  
try{ ;Kob]b  
Thread.sleep(nSecond); 01uMbtM  
} Y?a*-"  
catch(Exception e) ^1sX22k  
{ lTBPq?4{  
e.printStackTrace (); r({!ejT{U  
} sKVN*8ia  
} ]3u ErnI  
c=p`5sN)  
//日志 a ;WRTV  
public static void log(String sMsg) $1y8gm  
{ [*GIR0  
System.err.println(sMsg); aVNBF`  
} DK;p6_tT  
D~E1hr&Vd>  
a|Io)Qhr  
public static void log(int sMsg) eK PxSN Z  
{ z-$bce9*  
System.err.println(sMsg); ~8L*N>Y  
} osPJ%I`^  
} KHV5V3q4  
KCu@5`p  
=NMT H[  
/* kv{uf$X*ve  
**TestMethod.java Y&!M#7/'J3  
*/ ,7&`V=C  
package NetFox; @ *P$4c  
%{ WZ  
^ ]02)cK  
public class TestMethod { 1RpTI7  
l?2(c  
A{3Aw|;  
public TestMethod() $<cio X  
{ ///xx/weblogic60b2_win.exe G5a PjP  
try{ {|nm0vg`A  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |:BKexjHL  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fr_esx  
SiteFileFetch fileFetch = new SiteFileFetch(bean); &'4{/Gz  
fileFetch.start(); ;T0F1  
} $N4%I4  
catch(Exception e){e.printStackTrace ();} Z]kk.@P  
2[6>h)  
ky>0  
} cVya~ *  
*y<Ru:D  
__o`+^FS  
public static void main(String[] args) ]wFKXZeK  
{ ?@8[1$1a  
new TestMethod(); |W4 \  
} hqrI%%  
} C%_^0#8-0  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
10+5=?,请输入中文答案:十五