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
  • 9387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
/* #Ak9f-pf  
**SiteFileFetch.java KiC,O7&<  
*/ YLSDJ$K6  
package NetFox; /9P7;1?  
import java.io.*; _wW"Tn]  
import java.net.*; $mf6!p4  
ci 22fw0  
m<cv3dbZo  
public class SiteFileFetch extends Thread { Xfg?\j/  
^y|`\oyqwN  
=ty{ugM<  
SiteInfoBean siteInfoBean = null; //文件信息Bean V!+<  
long[] nStartPos; //开始位置 fbah~[5}  
long[] nEndPos; //结束位置 '?{L gj^R  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -I#<?=0B  
long nFileLength; //文件长度 m,w^,)  
boolean bFirst = true; //是否第一次取文件 }>YEtA  
boolean bStop = false; //停止标志 ^QHgc_oDm  
File tmpFile; //文件下载的临时信息 pMUUF5  
DataOutputStream output; //输出到文件的输出流 6BXZGE  
pm=s  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) UK@hnQU8`  
public SiteFileFetch(SiteInfoBean bean) throws IOException EW]8k@&g  
{ 6Ol)SQE,  
siteInfoBean = bean; `VglE?M  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ?$/W3Xn0%  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); w0<1=;_%  
if(tmpFile.exists ()) =1O;,8`  
{ ;1TQr3w  
bFirst = false; O4a~(*f  
read_nPos(); a][Tb0Ox  
} ('=Q[ua7-(  
else poqNiOm4%  
{ HGj[\kU~  
nStartPos = new long[bean.getNSplitter()]; ?#ywUEY* i  
nEndPos = new long[bean.getNSplitter()]; y,<\d/YY@  
} "*d%el\63  
%]F{aR  
/KO2y0`  
?i~mt'O  
} 6gq`V,  
nK]L0*s  
f~p[izt  
public void run() bD 1IY1  
{ L9z5o(Aa  
//获得文件长度 o O1Fw1Y  
//分割文件 i^}DIx{  
//实例FileSplitterFetch :pP l|"  
//启动FileSplitterFetch线程 6WLq>Jo  
//等待子线程返回 de"+ABR  
try{ 86Xf6Ea  
if(bFirst) T(+*y  
{ f2Tz5slE  
nFileLength = getFileSize(); 79'N/:.  
if(nFileLength == -1) dW|S\S'&  
{ 5 ^tetDz}  
System.err.println("File Length is not known!"); H|;BT  
} DwXSlsN3v  
else if(nFileLength == -2) 7 /DDQ  
{ k]A$?C0Q<%  
System.err.println("File is not access!"); {r?Ly15  
} M_;hfpJZ  
else N#X(gEV  
{ >>h0(G|  
for(int i=0;i<nStartPos.length;i++) XO/JnJ^B  
{ P"+K'B7K3  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Bbb_}y|CA  
} zSpL^:~  
for(int i=0;i<nEndPos.length-1;i++) NaR/IsN8%  
{ 8op,;Z7Y  
nEndPos = nStartPos[i+1]; ugZ-*e7  
} HW{si]~q  
nEndPos[nEndPos.length-1] = nFileLength; ,r&:C48 dI  
} Eagl7'x  
} "I)*W8wTn  
dKOW5\H'  
[ _jd  
//启动子线程 8f^QO:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (d L;A0L  
for(int i=0;i<nStartPos.length;i++) 63J_u-o  
{ XzX-Q'i=n0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Y&<psQeb  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1kiS."77x  
nStartPos,nEndPos,i); k,~I>qg  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HF3W,eaqK  
fileSplitterFetch.start(); QWo_Zg0"  
} xHA6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ] Q 'Ed  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7 +RsZu  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [a\U8 w  
nEndPos = " + nFileLength); vS! TnmF  
// fileSplitterFetch[nPos.length-1].start(); :V(+]<  
7rc6  
jLANv{"  
//等待子线程结束 w3l+BUn:X  
//int count = 0; lw.4O^  
//是否结束while循环 FD}hw9VyF@  
boolean breakWhile = false; d!V;\w  
[r_YQ*+ej  
^!={=No]  
while(!bStop) H%!ED1zpA  
{ m.F \Mn  
write_nPos(); ZB+N[VJs)  
Utility.sleep(500); kl0!*j  
breakWhile = true; ;3nR_6\  
<Ae1YHUY  
:'L^zGf  
for(int i=0;i<nStartPos.length;i++) MH"{N "|  
{ Mw0Kg9M  
if(!fileSplitterFetch.bDownOver)  #E[{  
{ 6D[m}/?Uy  
breakWhile = false; u afSz@`  
break; ICJp-  
} xKilTh_.6  
} ?!N@%R>5rN  
if(breakWhile) hdi/k!9[\  
break;  d"E@e21  
Mr5E\~K>s  
@~4Q\^;NX  
//count++; e?Pzhh a  
//if(count>4) 5 A/[x $q  
// siteStop(); Fk:yj 4'  
} %gF; A*  
!>~W5c^  
!+& Rn\e%7  
System.err.println("文件下载结束!"); b(hnouS  
} WUVRwJ 5  
catch(Exception e){e.printStackTrace ();} 5h"moh9tG  
} ZyJdz+L{@V  
-Y*"!8  
iIOA54!o  
//获得文件长度 ])d_B\)Kck  
public long getFileSize() ~1x,m.f8  
{ `/zx2Tkk  
int nFileLength = -1; a(+.rf;  
try{ k`LoRqF  
URL url = new URL(siteInfoBean.getSSiteURL()); W?a{3B   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j@JhxCe1+R  
httpConnection.setRequestProperty("User-Agent","NetFox"); uR|?5DK  
6Un61s  
-h5yg`+1N\  
int responseCode=httpConnection.getResponseCode(); Q(P'4XCm  
if(responseCode>=400) th@a./h"  
{ 6x1 !!X+)+  
processErrorCode(responseCode); .qjVw?E  
return -2; //-2 represent access is error s 0}OsHAj  
} @yBg)1AL  
7pB5o2CD0  
*Q?ZJS ~  
String sHeader; =j%B`cJ66_  
bB|UQaCl  
.hYrE5\-  
for(int i=1;;i++) `+IB;G1  
{ 6g/ <FM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2>l =oXq  
//Utility.log(in.readLine()); ~$#"'Tl4J  
sHeader=httpConnection.getHeaderFieldKey(i); (dOC ^i  
if(sHeader!=null) 1_D|;/aI  
{ QZcdfJck=+  
if(sHeader.equals("Content-Length")) ]9xuLJ)  
{ '@Zau\xC  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B8+J0jdg6%  
break; q Ee1OB  
} 8.-0_C*U;  
} w\ hl2JTy  
else pYtG%<  
break; 4!'1o`8vs  
} c7$L:  
} )7U^&I,  
catch(IOException e){e.printStackTrace ();} sSisO?F!Z  
catch(Exception e){e.printStackTrace ();} D& Xh|}2A  
q[6tvPfkX  
H%,jB<-.A  
Utility.log(nFileLength); w2-:!,X  
<ptgFR+  
m/,.3v  
return nFileLength; gy|L!_1Z8  
} QXXB>gOY5  
s}MD;V&0  
1Sk=;Bic  
//保存下载信息(文件指针位置) l(-We.:(  
private void write_nPos() C- Aiv@@<=  
{ Xb0$BAP  
try{ 72hN%l   
output = new DataOutputStream(new FileOutputStream(tmpFile)); #;9I3,@/Y  
output.writeInt(nStartPos.length); ?2hS<qXX  
for(int i=0;i<nStartPos.length;i++) ^[K3]*!@  
{ r-M:YB  
// output.writeLong(nPos); + .Pv:7gh  
output.writeLong(fileSplitterFetch.nStartPos); {Y>5 [gp  
output.writeLong(fileSplitterFetch.nEndPos); G ZxM44fP  
} a;=)`  
output.close(); 6jv_j[[  
} d~bZOy  
catch(IOException e){e.printStackTrace ();} XLEEd?Vct9  
catch(Exception e){e.printStackTrace ();} {!? @u?M  
} U(lcQC`$  
~U] "dbQ  
wul$lJ?tE  
//读取保存的下载信息(文件指针位置) K? ;_T$^K  
private void read_nPos() BCDmce`=l  
{ $XBn:0U  
try{ tUS)1*{_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]V|rOtxb  
int nCount = input.readInt(); 3 [R<JrO  
nStartPos = new long[nCount]; ^/nj2"  
nEndPos = new long[nCount]; }ll&qb  
for(int i=0;i<nStartPos.length;i++) W'aZw9  
{ UKYQ @m  
nStartPos = input.readLong(); F32N e6Y6"  
nEndPos = input.readLong(); 8v$ 2*$  
} XJx$HM&0M  
input.close(); N?xZ]?T  
} )e#KL$B)v  
catch(IOException e){e.printStackTrace ();}  =fJDFg  
catch(Exception e){e.printStackTrace ();} !Zo we*`  
} PUt\^ke  
C$"N)6%q  
Y(aEp_kV  
private void processErrorCode(int nErrorCode) !+sC'/  
{ #6t 4 vJ1  
System.err.println("Error Code : " + nErrorCode); /z<7gd~oU  
} 9q +I  
@DiXe[kI  
J1i{n7f=@  
//停止文件下载 pbfIO47ZC  
public void siteStop() f`r o {p  
{ [I*)H7pt}  
bStop = true; w %4SNR  
for(int i=0;i<nStartPos.length;i++) p>4tPI}bf  
fileSplitterFetch.splitterStop(); gYeKeW3)  
*QKxrg  
]!7 %)  
} ?]*WVjskE  
} 9CBKU4JQ  
//负责部分文件的抓取 r7Vt,{4/  
**FileSplitterFetch.java t>hoXn^-  
*/ 5yOIwzr&Uu  
package NetFox; t0*kL.  
fQW1&lFT  
se|>P=/  
import java.io.*; 1M1|Wp  
import java.net.*; `IP?w&k)  
\a<7DTV  
e"Y ( 7<  
public class FileSplitterFetch extends Thread { :;Lt~:0b~  
CbvP1*1  
[Lck55V+Q  
String sURL; //File URL v'Y0|9c  
long nStartPos; //File Snippet Start Position &a;{ed1B  
long nEndPos; //File Snippet End Position !,Ou:E?Bb  
int nThreadID; //Thread's ID uDtml$9rN  
boolean bDownOver = false; //Downing is over nt 9LBea  
boolean bStop = false; //Stop identical zd%n)jlwR  
FileAccessI fileAccessI = null; //File Access interface :B^YK].  
X;e=d+pw  
A-n@:` n~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException  Mi>!  
{ ZmLA4<  
this.sURL = sURL; pZE}<EX  
this.nStartPos = nStart; QN4{xf:}S  
this.nEndPos = nEnd; BlLK6"gJT  
nThreadID = id; .uh>S!X, ]  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]%%I=r  
} Z\YCjs%  
B$=oU   
Ow#a|@  
public void run() ]_"c_QG  
{ X!aC6gujOH  
while(nStartPos < nEndPos && !bStop) @AB}r1E2  
{ _i3?;Fds  
M]Kx g;  
tPp9=e2[s  
try{ :VkuK@Th`  
URL url = new URL(sURL); ;[qA?<GJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <?2g\+{s9  
httpConnection.setRequestProperty("User-Agent","NetFox"); CXQ+h  
String sProperty = "bytes="+nStartPos+"-"; 5dvP~sw  
httpConnection.setRequestProperty("RANGE",sProperty); WyA`V C  
Utility.log(sProperty); !W\za0p  
o+],L_Ab  
{yzo#"4Oy  
InputStream input = httpConnection.getInputStream(); |o@xWs@m  
//logResponseHead(httpConnection); Y>J$OA:  
q1a*6*YB  
T`zUgZ]  
byte[] b = new byte[1024]; x/S:)z%X  
int nRead; z|M+ FHl$  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C vOH*K'  
{ >g>L>{  
nStartPos += fileAccessI.write(b,0,nRead); T1-.+&<  
//if(nThreadID == 1) \ u*R6z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [ML|, kq!  
} ;aj4V<@  
.OM^@V~T  
A"3"f8P8a  
Utility.log("Thread " + nThreadID + " is over!"); 3(oB[9]s  
bDownOver = true; J16t&Ha`  
//nPos = fileAccessI.write (b,0,nRead); B>;`$-  
} +s j2C  
catch(Exception e){e.printStackTrace ();} .),Fdrg  
} 1!S*z^LGl  
} ;f!}vo<;  
(y^svXU}a  
SG4)kQ  
//打印回应的头信息 ?wi^R:2|j  
public void logResponseHead(HttpURLConnection con) )MWbZAI  
{ yC:C  
for(int i=1;;i++) qNuBK6E#4  
{ I.6 qA *  
String header=con.getHeaderFieldKey(i); , 3&D A  
if(header!=null) D7lRZb  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oypF0?!m  
Utility.log(header+" : "+con.getHeaderField(header)); 4=nh' U38  
else >ufLRGL>  
break; V[;^{,;  
} u|+Dqe`  
} #rI4\K  
)p`zN=t  
<~bvf A=  
public void splitterStop() ;%Zu[G`C  
{ Z#t}yC%^d  
bStop = true; o.g)[$M8cF  
} 01 <Ti"  
K'c[r0Ew  
V r7L9%/wg  
} I_s*pT  
4n0Iw  I  
Krd0Gc~\|  
/* wBlo2WY  
**FileAccess.java ;S?ei>Q  
*//文件访问(定位,写) 1>=]lMW  
package NetFox; mVd%sWD  
import java.io.*; K2qKkV@  
P,s>xM  
ce<88dL  
public class FileAccessI implements Serializable{ xUF5  
B!x7oD9  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5h l!zA?  
RandomAccessFile oSavedFile; #|QA_5  
long nPos; j a'_syn  
|/%X8\  
S[e> 8  
public FileAccessI() throws IOException zi_0*znw  
{ {U)q)  
this("",0); yIu_DFq%  
} a_ \t(U  
O?f?{Jsx  
u\3=m%1  
public FileAccessI(String sName,long nPos) throws IOException -`CE;  
{ {%D4%X<  
oSavedFile = new RandomAccessFile(sName,"rw"); ':7gYP*v  
this.nPos = nPos; Y~B-dx'V  
oSavedFile.seek(nPos); d$HPpi1LL  
} ATF>"Ux  
w\1K.j=>|N  
lNo]]a+_  
public synchronized int write(byte[] b,int nStart,int nLen) x"P@[T  
{ qK)T#sh  
int n = -1; g!;a5p6  
try{ zwJ\F '  
oSavedFile.write(b,nStart,nLen); /[I#3|  
n = nLen; J%IKdxa  
} owzcc-g  
catch(IOException e) R9-Uoc/  
{ 9*S9~  
e.printStackTrace (); cDq*B*e  
} 0"l`M5-KP  
+' SG$<Xv  
&<EixDi4q  
return n; &&7&/   
} 07G'"=  
r<[G~n  
hf:\^w  
} T*%O\&'r  
v+~O\v5Q  
"I QM4:  
/* x~ E\zw  
**SiteInfoBean.java E/2_@&U:}  
*/ `Krk<G  
package NetFox; y=2nV  
m>f8RBp]'  
0|| 5 r#  
public class SiteInfoBean { 32p9(HQ  
,rX|_4 n*  
@!*I mNMI  
private String sSiteURL; //Site's URL 0.&-1pw  
private String sFilePath; //Saved File's Path ;!B,P-Z"g  
private String sFileName; //Saved File's Name bb}Fu/S  
private int nSplitter; //Count of Splited Downloading File _2WW0  
A$n:   
<m> m"|G  
public SiteInfoBean() 5nXmaj  
{//nSplitter的缺省值为5 t4UL|fI  
//default value of nSplitter is 5 V6&6I  
this("","","",5); J; N\q  
} ~!P&LZ  
F{E`MK~f_  
j9R+;u/!  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RBpv40n0  
{ k54b@U52 h  
sSiteURL= sURL; pp+z5  
sFilePath = sPath; _adW>-wQ!d  
sFileName = sName; Y/f8rN  
this.nSplitter = nSpiltter; Zfd `Fu  
v,Z?pYYo  
x b!&'cw  
} s=Xg6D  
Ap> H-/C  
l6N"{iXU  
public String getSSiteURL() SP;1XXlL  
{ aWY#gI{  
return sSiteURL; k{ulu  
} & kQj)  
P"|-)d  
|Y30B,=M  
public void setSSiteURL(String value) ^nLk{<D35  
{ ~&WBA]w'+  
sSiteURL = value; *9US>mVy  
} |=[. _VH1  
@xr}(.  
jP.dQj^j&  
public String getSFilePath() G[]h1f!  
{ v)~!HCG  
return sFilePath; 2BO"mc<#$  
} 7 b{y  
XdE|7=+s  
s0'6r$xj  
public void setSFilePath(String value) SP4(yJy&  
{ P&Wf.qr{:  
sFilePath = value; YoSBS   
} X$=/H 6R5Z  
]+Z,HY@;-  
>6|Xvtf  
public String getSFileName() %?J-0  
{ ZQyXzERp  
return sFileName; B;t{IYhq{  
} (d['f]S+&  
|eksvO'~  
+*G<xW :M  
public void setSFileName(String value) $\L=RU!c}  
{ j07b!j:"\}  
sFileName = value; } a!HbH  
} cHJ4[x=  
Y8/&1s_  
u6 4{w,  
public int getNSplitter() p+CK+m   
{ pwl7aC+6d  
return nSplitter; ufN`=IJ%  
} x5k6"S"1,  
`82^!7!  
"YN6o_*]  
public void setNSplitter(int nCount)  dK]#..  
{ o[g]Va*8  
nSplitter = nCount; ue -a/a  
} G*g*+D[HM  
} WyUa3$[gO  
&<# ,J4  
jWK>=|)=c  
/* 54Vb[;`Kkb  
**Utility.java n66b(6"mO2  
*/ UW&K\P  
package NetFox; Mr@{3do$  
c LfPSA  
E0eZal],  
public class Utility { Dk}txw}#  
5KW n>n  
6>[J^k%~w)  
public Utility() CIQ9dx7>  
{ G5UNW<P2C  
v %S$5  
-pQ0,/}K  
} uCj)7>}v{M  
2,p= %  
//线程睡眠 IeB^BD+j  
public static void sleep(int nSecond) V5+|H1=  
{ 9L>ep&u)^  
try{ uExYgI`<%&  
Thread.sleep(nSecond); [pz1f!Wn  
} v"dl6%D"  
catch(Exception e) B \.0 5<  
{ US&:UzI.  
e.printStackTrace (); B~%SB/eu  
} B] PG  
} FB O_B  
wdRk+  
//日志 >viLvDng  
public static void log(String sMsg) o:@A%*jg  
{ VW:Voc  
System.err.println(sMsg); >| hqt8lY  
} Agwl2AM5k  
Pk^V6-  
fjHd"!)3  
public static void log(int sMsg) )SfM`W)Y  
{ >ajcfG .k(  
System.err.println(sMsg); D"P<;@ef  
} o 'Z W  
} :-j/Y'H_  
qR^+K@ *|  
C`\yc_b9Pf  
/* -IL' (vx  
**TestMethod.java {%z5^o1)  
*/ 7/bF0 4~%  
package NetFox; la{o<||Aq  
lht :%Ts$  
`91?^T;\F  
public class TestMethod { l(~NpT{=V  
z[0t%]7l  
($[@'?Z1  
public TestMethod() _:G>bU/^  
{ ///xx/weblogic60b2_win.exe Yz>8 Nn'_  
try{ ZU5;w  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V""3#Tw   
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SKJ'6*6  
SiteFileFetch fileFetch = new SiteFileFetch(bean); sfC/Q"Zs  
fileFetch.start(); #ihHAiy3  
} uC"Gm;0  
catch(Exception e){e.printStackTrace ();} 8e_9u@p+w  
||#+ ^p7G  
(o!i9)  
} K# h7{RE  
RYM[{]4b5F  
/[|A(,N}{  
public static void main(String[] args) ?aU-Y_pMe  
{ E>kgEfzxP  
new TestMethod(); UL3u2g;d  
} e_llW(*l8^  
} #G("Oh  
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
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五