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
  • 8988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
/* P-+^YN,  
**SiteFileFetch.java (&njZdcb*  
*/ ;GH(A=}/Y  
package NetFox; fF-V=Zf5  
import java.io.*; :^l*_v{  
import java.net.*; 2$T~(tem  
R L)'m  
) }?dYk  
public class SiteFileFetch extends Thread { qIb(uF@l"  
laFkOQI  
M~"]h:m&'v  
SiteInfoBean siteInfoBean = null; //文件信息Bean hrS/3c'<Z  
long[] nStartPos; //开始位置 ~x4Y57  
long[] nEndPos; //结束位置 jg%D G2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 XZKOBq B]  
long nFileLength; //文件长度 ghms-.:b8  
boolean bFirst = true; //是否第一次取文件 mcr71j  
boolean bStop = false; //停止标志 9F,jvCM63  
File tmpFile; //文件下载的临时信息 .3ic%u;|D  
DataOutputStream output; //输出到文件的输出流 <JKPtF2b  
}jIb ^|#CD  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) K"g[%O<  
public SiteFileFetch(SiteInfoBean bean) throws IOException #jDO?Y Sa  
{ 55,vmDd  
siteInfoBean = bean; QFX|ZsmK  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); rbP.N ?YU%  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); vo0[Z,aH5  
if(tmpFile.exists ()) Q{$2D&  
{ )dlt$VX  
bFirst = false; *&5G+d2  
read_nPos(); !w C4ei`  
} Nc;7KMOIA  
else ](Sp0t  
{ xmVK{Q YT$  
nStartPos = new long[bean.getNSplitter()]; 8,['q~z  
nEndPos = new long[bean.getNSplitter()]; 8|J%IE  
} }>tUkXlhJ<  
\!w7 N :m  
-n Hc52,  
i uN8gHx  
} 08.dV<P  
` $zi?A:j  
sZB$+~.:}  
public void run() c*ytUI *  
{ >6rPDzW`Dx  
//获得文件长度 ?cpID8Z  
//分割文件 !).D  
//实例FileSplitterFetch 3}N:oJI$z  
//启动FileSplitterFetch线程 Kt`0vwkjvI  
//等待子线程返回 ,l@hhaLm?  
try{ ^8fO3<Jg  
if(bFirst) ;)cl Cm46  
{ Ex<-<tY  
nFileLength = getFileSize(); hPEK@  
if(nFileLength == -1) ){wE)NN  
{ }O!LTD  
System.err.println("File Length is not known!"); RS$:]hxd>_  
} ,:;_j<g`e  
else if(nFileLength == -2) xQ$*K]VP  
{ v"bOv"!al  
System.err.println("File is not access!"); yWX:`*GV  
} ^M,Q<HL  
else T> 1E  
{ Yoaz|7LS  
for(int i=0;i<nStartPos.length;i++) "}ZD-O`!  
{ { >4exyu6  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); $/pd[H[{  
} lYJ]W[!  
for(int i=0;i<nEndPos.length-1;i++) fQe-v_K  
{ <M 7WWtmx  
nEndPos = nStartPos[i+1]; ?= ulf GrY  
} R%5\1!Fl=G  
nEndPos[nEndPos.length-1] = nFileLength; ' ;$2j~  
} vB#3jI  
} FTk!Mn88  
&&>OhH`  
.@xwl}o$OL  
//启动子线程 Z!hDTT  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;AHa|35\  
for(int i=0;i<nStartPos.length;i++) H!s &]b  
{ 1Z*-@%RX  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZT|E1[Q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~+4OG 0  
nStartPos,nEndPos,i); r5rK>  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bup;4~g  
fileSplitterFetch.start(); Ig S.U  
} O":x$>'t  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /Nxy?g|,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s V{[~U,|  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !d"J,.)  
nEndPos = " + nFileLength); 9ft7  
// fileSplitterFetch[nPos.length-1].start(); ,.F,]m=  
uTn(fs) D  
<0Q`:'\.>  
//等待子线程结束 pU}>}  
//int count = 0; 7@C :4c@0  
//是否结束while循环 V! ~uGf  
boolean breakWhile = false; 8$@gAlI^  
jaNkWTm :  
)Ax1?Nx$  
while(!bStop) 6Zkus20  
{ C2!POf;GdN  
write_nPos(); x?f3XEA_  
Utility.sleep(500); h-#Glse<  
breakWhile = true; bJGT^N@  
w^P4_Yr  
8l)^#"ySA  
for(int i=0;i<nStartPos.length;i++) W;u~}k<  
{ GHH1jJ_[7  
if(!fileSplitterFetch.bDownOver) 5\qoZs*e  
{ : h-N  
breakWhile = false; du`],/ 6  
break; ,mjwQ6:Ny  
} whxE[Xnv  
} z <s]Z  
if(breakWhile) iB[%5i-  
break; \6nWt6M  
=>/aM7]  
! QP~#a%  
//count++; 2h u;N  
//if(count>4) zFwp$K>{QY  
// siteStop(); 2&06Db(  
} D4;V8(w=#  
0xZq?9a  
m {wMzsQ  
System.err.println("文件下载结束!"); >qCUs3}C{*  
} ZZ?=^g  
catch(Exception e){e.printStackTrace ();} )2u=U9  
} c7P"1  
Hg]Q.SeJ(  
+7d%)t  
//获得文件长度 u;;]S!:M  
public long getFileSize() j$Gb> Ex>  
{ @yS  
int nFileLength = -1; rhwY5FD?  
try{ -=O9D- x=  
URL url = new URL(siteInfoBean.getSSiteURL()); )O2giVq7[0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A)s  
httpConnection.setRequestProperty("User-Agent","NetFox"); B,, f$h!  
h#'(UZ  
Kh'/Ne?  
int responseCode=httpConnection.getResponseCode(); [6)`wi  
if(responseCode>=400) >*B/Wy  
{ DRj\i6-v  
processErrorCode(responseCode); z(K[i?&  
return -2; //-2 represent access is error 7*~ rhQ  
} >jRz4%  
N>'1<i?  
#&5m=q$EI  
String sHeader; D=o9+5Slw  
?L+@?fVN  
?4(uwX p  
for(int i=1;;i++) 3zGxe-  
{ HG5|h[4Gt  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lm o>z'<  
//Utility.log(in.readLine()); O jr{z  
sHeader=httpConnection.getHeaderFieldKey(i); M E4MZt:>  
if(sHeader!=null) -Q<3Q_  
{ G6]M~:<i  
if(sHeader.equals("Content-Length")) -=s7Q{O8Z  
{ o_vK4%y(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wVP{R3  
break; <dLdSEw  
} +\?#8U/k  
} u&m B;:&  
else `.>2h}op  
break; E<>n0",  
} (Lo<3a-]  
} <RKh%4#~  
catch(IOException e){e.printStackTrace ();} =YE"6iU  
catch(Exception e){e.printStackTrace ();} blk ~r0.2  
:L&-  
YFy5>*W  
Utility.log(nFileLength); S%R:GZEf_  
xT#j-T  
%j^[%&pT  
return nFileLength; =Bu d!  
} .3Jggp  
#x" 4tI  
r> eOq[z  
//保存下载信息(文件指针位置) 0jro0f'  
private void write_nPos() {ckA  
{ mrS:|| ,_  
try{ gmJiKuAL5  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xv|~1v%s7  
output.writeInt(nStartPos.length); k?o(j/  
for(int i=0;i<nStartPos.length;i++) I)U|~N  
{ ^ RU"v>  
// output.writeLong(nPos); "|gNNmr  
output.writeLong(fileSplitterFetch.nStartPos); APsd^J  
output.writeLong(fileSplitterFetch.nEndPos); r2]:'O6  
} vbXuT$  
output.close(); 3&/5!zOg)  
} (B.J8`h }  
catch(IOException e){e.printStackTrace ();} t.v@\[{ -  
catch(Exception e){e.printStackTrace ();} S6*3."Sk  
} LBk1Qw}-  
6-{QU] #  
RM|<(kq  
//读取保存的下载信息(文件指针位置) >t.2!Z_RQ  
private void read_nPos() N0,.cd]y`  
{ l Ztq_* Fl  
try{ 5#p [Q _  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C%85Aq*4  
int nCount = input.readInt(); t \kI( G  
nStartPos = new long[nCount]; {*bXO8vi((  
nEndPos = new long[nCount]; EX7gTf#  
for(int i=0;i<nStartPos.length;i++) \SkCsE#H  
{ osB[KRT>("  
nStartPos = input.readLong(); f>g>7OsD]  
nEndPos = input.readLong(); !G.)%+Z  
} $cHA_$ `  
input.close(); MM"{ehd{^a  
} i:0~%X  
catch(IOException e){e.printStackTrace ();} Ev|2bk \  
catch(Exception e){e.printStackTrace ();} #(FG+Bk  
} ]i3 2-8%  
6 :K~w<mMJ  
44B)=p7  
private void processErrorCode(int nErrorCode) ZY-W~p1:G  
{ u~=>$oT't  
System.err.println("Error Code : " + nErrorCode); y,v*jE  
} ZC'(^liAp  
`So*\#\T  
;?"2sS!AHQ  
//停止文件下载 UbE*x2N  
public void siteStop() j y R 9a!  
{ a938l^@;s8  
bStop = true; !>W _3Ea  
for(int i=0;i<nStartPos.length;i++) \74+ cN  
fileSplitterFetch.splitterStop(); LRW7_XYz  
%Ak"d+OH4  
23 BzD^2a  
} m!L&_ Z|j  
} c7.%Bn,  
//负责部分文件的抓取 f5<qF ]Y/  
**FileSplitterFetch.java 8Ih+^Y a  
*/ 3yn>9qt  
package NetFox; N|Mzj|i.  
HWG5Ghu8,)  
ZgVYC4=Q-\  
import java.io.*; p@!{Sh  
import java.net.*; _@wXh-nc  
#Y`GWT1==  
avrf]raM|  
public class FileSplitterFetch extends Thread { */fmy|#   
O$ui:<]dS  
f l*]ua  
String sURL; //File URL 7'uuc]\5>  
long nStartPos; //File Snippet Start Position }a6tG  
long nEndPos; //File Snippet End Position RI9&KS  
int nThreadID; //Thread's ID ;2 y3i5^k  
boolean bDownOver = false; //Downing is over ?(UeWLC#  
boolean bStop = false; //Stop identical >xb}AY;  
FileAccessI fileAccessI = null; //File Access interface m?VA 1  
c,-3+b  
oMk6ZzZ,>  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cL}} ^  
{ MgyV {`  
this.sURL = sURL; ZE863M@.  
this.nStartPos = nStart; T+7-6y+ d  
this.nEndPos = nEnd; 6Ty;m>j  
nThreadID = id; `3m7b!0k  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J24<X9b  
} 'F.Da#st!}  
D&KRJQ/  
,\ [R\s  
public void run() C&?Z\$ -/  
{ {?yZdL:m)  
while(nStartPos < nEndPos && !bStop) |Am +f.  
{ L ldZ"%P  
=0!PnBGYn  
Dz4e.tvN  
try{ ~Ry?}5&:  
URL url = new URL(sURL); n?'I&0>M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %" kF i  
httpConnection.setRequestProperty("User-Agent","NetFox"); uL| Wuq  
String sProperty = "bytes="+nStartPos+"-"; yh~*Kt]9Ya  
httpConnection.setRequestProperty("RANGE",sProperty); Ud@D%?A7  
Utility.log(sProperty); .)J7 \z8m  
tP/0_^m  
_M[@a6?  
InputStream input = httpConnection.getInputStream(); i[,9hp  
//logResponseHead(httpConnection); IL*Ghq{/  
>G `Uc&=  
xv|?;Zf6w  
byte[] b = new byte[1024]; tgk] sQY  
int nRead; zY_?$9l0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mk*r^k`a  
{ <!@*2/Q]J]  
nStartPos += fileAccessI.write(b,0,nRead); "QCtF55X&  
//if(nThreadID == 1) DXFU~J*  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]=Im0s  
} SLI(;, s  
/Mq9~oC  
}.`no  
Utility.log("Thread " + nThreadID + " is over!"); s}3g+T\l1w  
bDownOver = true; DAYR=s  
//nPos = fileAccessI.write (b,0,nRead); b2rlj6d  
} ?fv5KdD  
catch(Exception e){e.printStackTrace ();} VS.~gHx  
} Jkf%k3H3I*  
} F_C7S  
PD,s,A  
`X;'*E]e  
//打印回应的头信息 ,v<GSiO  
public void logResponseHead(HttpURLConnection con) 7nsn8WN[  
{ ( x)}k&B;  
for(int i=1;;i++) <V?csx/eRd  
{ @-B)a Z  
String header=con.getHeaderFieldKey(i);  al#BfcZW  
if(header!=null) =17d7#-  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0<ze'FbV]  
Utility.log(header+" : "+con.getHeaderField(header)); Vc2 (R^  
else ,hO*W-a% 1  
break; 3:H[S_q  
} S=f:-?N|  
} UYLCzv~W  
,oin<K  
:`jB1rI  
public void splitterStop() goa@ e  
{ /2s=;tA1  
bStop = true; Hsdcv~Xr;l  
}  kD}w5 U  
ZwzN=03T  
u4eA++ eT  
} GvB;o^Wd  
/w|!SZB  
V= wWY*C  
/* HGiO}|q :  
**FileAccess.java  ,>C`|  
*//文件访问(定位,写) ;*J_V/&?  
package NetFox; o54/r#~fi  
import java.io.*; Yee% <<S  
%2q0lFdcM  
0gevn  
public class FileAccessI implements Serializable{ 6y0CEly>3#  
;xXD2{q  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ffH]`N  
RandomAccessFile oSavedFile; J]AkWEiCJ  
long nPos; J=l\t7w  
*#y9P ve  
f*%Y]XL;%  
public FileAccessI() throws IOException TWU[/ >K  
{ r$Tu``z \  
this("",0); qpEK36Js  
} XJSI/jpa@  
&m PR[{  
;#/Uo8  
public FileAccessI(String sName,long nPos) throws IOException !_P-?u  
{ #{8t ?v l  
oSavedFile = new RandomAccessFile(sName,"rw"); +|K/*VVn`  
this.nPos = nPos; [gkOwU=?  
oSavedFile.seek(nPos); Zws[C  
}  8MZ:=  
lWyg_YO@  
n1Z*wMwC  
public synchronized int write(byte[] b,int nStart,int nLen) 8V?*Bz-4`  
{ xo GX&^=  
int n = -1; 7*MjQzg-P  
try{ O$*\JL  
oSavedFile.write(b,nStart,nLen); yDORL| E'  
n = nLen; ?PSJQ3BC|  
} Tfytc$aQ  
catch(IOException e) "KHe6otmi_  
{ I9ZJ"29  
e.printStackTrace (); j>I.d+   
} s$3WJ'yr  
e~1$x`DH  
77/j}Pxh  
return n; }C'h<%[P  
} 0l'"idra  
ugy:^U  
c#L.I  
} b~td ^  
zI& ).  
k:yrh:JhB  
/* C"cBlru8B  
**SiteInfoBean.java .4%6_`E  
*/ CubBD+h l*  
package NetFox; ]vQU(@+I  
JTS<n4<a  
5T-CAkR{n  
public class SiteInfoBean { 8b|m66#|  
s~b!3l`gu  
@|;XDO`k;  
private String sSiteURL; //Site's URL +'`I]K>  
private String sFilePath; //Saved File's Path Yw6d-5=:  
private String sFileName; //Saved File's Name W5U;{5  
private int nSplitter; //Count of Splited Downloading File !#TM%w  
k:0nj!^4w>  
*USzzLq  
public SiteInfoBean() XJguw/[wm  
{//nSplitter的缺省值为5 +rOfQ'lQ  
//default value of nSplitter is 5 btDPP k'  
this("","","",5); o%3VE8-  
} j\%m6\{n|  
=|O><O|  
Aw,#oG {N  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f eA(Rj  
{ +V,Ld&r  
sSiteURL= sURL; pP^"p"<s  
sFilePath = sPath; E>L_$J-A-  
sFileName = sName; HI!bq%TZ4  
this.nSplitter = nSpiltter; 2O+fjs  
Y}hz UKJ  
hB1Gtc4n  
} I`KBj6n  
G_5E#{u  
1vL$k[^&d  
public String getSSiteURL() x67,3CLy?  
{ )A*Sl2ew  
return sSiteURL; ?t"bF:!  
} n1@ Or=5  
oh%/\Xu  
wg{Y6X yH  
public void setSSiteURL(String value) Mb\[` 4z  
{ e*/ya8p?  
sSiteURL = value; BDc "0XH  
} c 6$n:  
kOLS<>.  
9 ?(P?H  
public String getSFilePath() !k0t (.  
{ :}[[G2|9  
return sFilePath; TM$Ek^fQ.  
} mqv!"rk'w  
F/chE c V  
S$%Y{  
public void setSFilePath(String value) ]zR,Y= #  
{ ~glFB`?[  
sFilePath = value; 8+U':xR  
} 90]{4]y;  
ealh>Y  
[0-zJy|,  
public String getSFileName() Jm {~H%  
{ <#5`%sa '  
return sFileName; hP]zC1s  
} %{K6   
u9^R ?y  
_.ELN/$-  
public void setSFileName(String value) t.tdY  
{ "Qxn}$6-  
sFileName = value; :O{oVR  
} `Ef &h V  
^><B5A>;  
,O}2LaK.O  
public int getNSplitter() YcJ2Arml  
{ js8GK  
return nSplitter; "K*+8 IO2  
} WX9pJ9d  
) bPF@'rF2  
-"Q[n,"Y  
public void setNSplitter(int nCount) Y'S9   
{ X>6VucH{\  
nSplitter = nCount; 9,;+B8-A  
} R@H}n3,  
} BlvNBB1^  
!WReThq  
^Wz3 q-^  
/* [j`-R 0Np  
**Utility.java Cb/?hT  
*/ @5-+>\Hd^t  
package NetFox; p; ZEz<M  
Q|W!m0XO  
: j m|)  
public class Utility { 7OOod1  
tHo0q<.oX  
5`3f"(ay/  
public Utility() .5m^)hi  
{ ^. i;,  
M B,P#7|  
f3]u-e'b  
} H9Pe,eHs  
1yIo 'i1  
//线程睡眠 .DkDMg1US  
public static void sleep(int nSecond) L5*,l`lET  
{ "yCek  
try{ A*:(%!  
Thread.sleep(nSecond); |fk,&5s  
} @9rmm)TZ  
catch(Exception e) NX*9nwp^  
{ Eh)VU_D  
e.printStackTrace (); "rA: ;ntz  
} fJ3qL# '  
} YMx zj  
;Q.g[[J/p  
//日志 {@u}-6:wAT  
public static void log(String sMsg) m 5NF)eL  
{ ;,h*s, i  
System.err.println(sMsg); IBzHXa>75  
} ptmPO4f  
Ueyt}44.e2  
D{,B[5  
public static void log(int sMsg) "lf_`4  
{ ]41G!'E=  
System.err.println(sMsg); uhLg2G^h  
} ^JMSe-  
} :6z0Ep"  
BVC{Zq6hi  
Fq5);sX=  
/* 0OMyE9jJJ  
**TestMethod.java []Z| *+=Q  
*/ (;T; ?v`-  
package NetFox; 1LjYV  
s geP`O%  
<>JDA(F"  
public class TestMethod { >gr6H1  
!P!|U/|c  
[VPqI~u5)  
public TestMethod() y tmlG%  
{ ///xx/weblogic60b2_win.exe `q exEk@S  
try{ V_(?mC  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dg#Ab8  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b['TRYc=:  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ):+H`Hcm  
fileFetch.start(); 79%${ajSI  
} /d >fp  
catch(Exception e){e.printStackTrace ();} Z3R..vy8  
?#kI9n<O  
-c=IO(B/  
} T[XI  
5.|rzk>  
w'5~GhnP+  
public static void main(String[] args) xL>0&R  
{ =I/J !}.  
new TestMethod(); ZF;S}1  
} 5Tp n`2F  
} |U^ ff^]  
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