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
  • 11380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
/* 9XUk.Nek  
**SiteFileFetch.java f6PYB&<1  
*/ 9Q 7342  
package NetFox; Zvra >%  
import java.io.*; Kb'4W-&u!  
import java.net.*; +HgyM0LFg  
^SM5oK  
u 7 <VD  
public class SiteFileFetch extends Thread { *uKYrs [  
u_FN'p=.  
BQs\!~Ux2  
SiteInfoBean siteInfoBean = null; //文件信息Bean !"'6$"U\K  
long[] nStartPos; //开始位置 z<J2e^j  
long[] nEndPos; //结束位置 RS@G.|  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 :u)Qs#'29  
long nFileLength; //文件长度 YHxQb$v)  
boolean bFirst = true; //是否第一次取文件 qt4%=E;[  
boolean bStop = false; //停止标志 ,4;'s  
File tmpFile; //文件下载的临时信息 Mq#Hi9SKY  
DataOutputStream output; //输出到文件的输出流 .LbAR u  
46B'Ec  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Q:'r p  
public SiteFileFetch(SiteInfoBean bean) throws IOException BH}M]<5  
{ tGSX TF}G  
siteInfoBean = bean; KUU ZN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ][XCpJ)8  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 5@pLGMHT  
if(tmpFile.exists ()) (CAkzgTfc  
{ ?D(aky#cyc  
bFirst = false; 5'<a,,RKu  
read_nPos(); voJJoy%  
} 7I;0 %sVQ{  
else O[p c$Pi  
{ BA8!NR|  
nStartPos = new long[bean.getNSplitter()]; =F5zU5`i  
nEndPos = new long[bean.getNSplitter()]; Zcg-i:@  
} ,C:^K`k&  
*r7%'K{ C  
v] m`rV8S[  
EiyHZ  
} %MEWw  
+"|TPKas  
,D&-.`'E  
public void run() D z[ ,;  
{ 7 h>,  
//获得文件长度 Zlygx  
//分割文件 R0G!5>1i  
//实例FileSplitterFetch >X5RRSo  
//启动FileSplitterFetch线程 Kk|)N3AV:  
//等待子线程返回 "I@akM$x  
try{ -KZ9TV # R  
if(bFirst) ;wZplVB7y  
{ xlh<}V tp  
nFileLength = getFileSize(); K~fWZT3]  
if(nFileLength == -1) l%qh^0  
{ by$mD_sr  
System.err.println("File Length is not known!"); rqKK89fD'  
} M-e|$'4u  
else if(nFileLength == -2) Z4m+GFY  
{ Cm0K-~ U  
System.err.println("File is not access!"); FV/lBWiQQ  
} _<l)4A3rS  
else 0C6T>E7  
{ 7y$U$6  
for(int i=0;i<nStartPos.length;i++) ME.!l6lm\  
{ Qtt3;5m  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |D[LU[<C  
} 3{TE6&HIa  
for(int i=0;i<nEndPos.length-1;i++) zy|h1 .gd  
{ Z2-"NB  
nEndPos = nStartPos[i+1]; aY DM)b}  
} =4OV }z=I  
nEndPos[nEndPos.length-1] = nFileLength; }C$D-fH8sW  
} `3z6y& dmx  
} 1bjWWNzQA  
Pjq()\/[Z  
f=Oj01Ut*  
//启动子线程 N9u {)u  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4E$d"D5]>p  
for(int i=0;i<nStartPos.length;i++) \{qtdTd  
{ 9S<V5$}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z@AN0?,`~o  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7Jpq7;  
nStartPos,nEndPos,i); AE Abny q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V@\u<LO0G  
fileSplitterFetch.start(); c<{~j~+  
} cs[nFfM  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h dqr~9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $8Z4jo  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S7@/d HN  
nEndPos = " + nFileLength); sWi4+PAM0  
// fileSplitterFetch[nPos.length-1].start(); Sae*VvT6  
&4*f28 s  
<y#@v  G  
//等待子线程结束 `9A`pC  
//int count = 0; J6@RIia  
//是否结束while循环 CX ; m8  
boolean breakWhile = false; H;+98AIy`  
6p.y/LMO  
5fLp?`T  
while(!bStop) 29&F_  
{ Bp4#"y2  
write_nPos(); ?/(*cA  
Utility.sleep(500); *T.V5FB0S  
breakWhile = true; 9Fg:   
.Y }k@T40a  
+6L.a3&(b  
for(int i=0;i<nStartPos.length;i++) cs4IO O$  
{ }|j#C[  
if(!fileSplitterFetch.bDownOver) G{zxP%[E  
{ _*xY>?Aq  
breakWhile = false; y`cL3 xr4R  
break; '}q/;}ih  
} Gq7\b({=  
} eu//Q'W  
if(breakWhile) *g4Uo{  
break; .Vs|&c2im  
>;}(? +|f  
X9rao n  
//count++; KXBTJ&  
//if(count>4) g3Ul'QJ  
// siteStop(); 7_eV.'h  
} L:.Rv0XT  
{yMkd4v  
"S>VqvH3  
System.err.println("文件下载结束!"); V=Z%y$1Bc  
} iaQFVROu  
catch(Exception e){e.printStackTrace ();} Z5`V\$  
} QJI]@3 Y  
EEvi_Z932  
HaF&ooI5+  
//获得文件长度 !lp7}[k<y  
public long getFileSize() sGa "  
{ Vq^b_^  
int nFileLength = -1; BU|m{YZ$  
try{ /)4Q%Zp  
URL url = new URL(siteInfoBean.getSSiteURL()); xX8 c>p  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @2>ce2+  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]#rN z"  
1\/~>  
AU;Iif6  
int responseCode=httpConnection.getResponseCode(); x@x5|8:ga  
if(responseCode>=400) %Kh}6   
{ @}' ?o_/C  
processErrorCode(responseCode); @k/|%%uP  
return -2; //-2 represent access is error I,r0K]  
} .fK~IKA  
"po;[ Ia2  
c#@L~<  
String sHeader; \t? ;p-+ta  
r/QI-Cf&  
I}awembw g  
for(int i=1;;i++) u5`b")a  
{ T ^/\Rr  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qr~zTBT] E  
//Utility.log(in.readLine()); P7 5@Yu(  
sHeader=httpConnection.getHeaderFieldKey(i); *~.'lE%[U  
if(sHeader!=null) ~ x J#NC+  
{ Xod/GY G  
if(sHeader.equals("Content-Length")) Q{ { =  
{ ,<TJh[TzC6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #.LI `nYA  
break; n+ s=u$%qn  
} Tq8U5#NF  
} g$z6*bL  
else =n;LP#(h?  
break; G%CS1#  
} +5%ncSJx  
} V! .I>  
catch(IOException e){e.printStackTrace ();} H<q z rO  
catch(Exception e){e.printStackTrace ();} tNAmA  
>B.KI}dE  
dSS Ai |}  
Utility.log(nFileLength); nr&9\lG]G  
|WgFLF~k  
a24(9(yh  
return nFileLength; +;q` A 1  
} =$_kkVQ$  
p;mV?B?oAQ  
`*B6T7p1  
//保存下载信息(文件指针位置) ^Jc|d,u;s  
private void write_nPos() 1=^|  
{ ayN[y  
try{ LVy (O9g  
output = new DataOutputStream(new FileOutputStream(tmpFile)); b >'c   
output.writeInt(nStartPos.length); O`;o"\P<  
for(int i=0;i<nStartPos.length;i++) Z[kVVE9b?  
{ j(c;r>  
// output.writeLong(nPos); )t,efg  
output.writeLong(fileSplitterFetch.nStartPos); `mquGk|)  
output.writeLong(fileSplitterFetch.nEndPos); tHFUV\D;,  
} EIOP+9zP  
output.close(); C`8.8  
} l_ LH!Tu  
catch(IOException e){e.printStackTrace ();} ZtpbKy!\$B  
catch(Exception e){e.printStackTrace ();} "}0)~,{x B  
} ! z5Ozm+}  
- R`nitf  
;20sh^~  
//读取保存的下载信息(文件指针位置) JRDIGS_~  
private void read_nPos() ^+Vf*YY 8  
{ /^`d o3a}  
try{ LXRIo2ynuw  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $Ut1vp1$  
int nCount = input.readInt(); DyRU$U  
nStartPos = new long[nCount]; e )]  
nEndPos = new long[nCount]; =b Q\BY#  
for(int i=0;i<nStartPos.length;i++) Bey9P)_Of  
{ :=K+~?  
nStartPos = input.readLong(); gbu)bqu2x  
nEndPos = input.readLong(); z/pxZ B ~"  
} 0 R>!jw  
input.close(); jori,"s  
} +Ecn  
catch(IOException e){e.printStackTrace ();} qh6Q#s>tH  
catch(Exception e){e.printStackTrace ();} O/oLQoH  
} 161IWos  
QL-E4]   
[`1@`5SL-  
private void processErrorCode(int nErrorCode) w1+ %+x  
{ &InFC5A  
System.err.println("Error Code : " + nErrorCode); gbFHH,@  
} (^~~&/U_U$  
+y 48.5  
E/^N   
//停止文件下载 ~{t<g;F  
public void siteStop() .nei9Y*  
{ 6N/6WrQEeg  
bStop = true; ",S146Y+  
for(int i=0;i<nStartPos.length;i++) ~@"H\):/  
fileSplitterFetch.splitterStop(); 1CS\1[E  
i8=+ <d  
I@(3~ Ab  
} *~zB{  
} $/Llzpvny  
//负责部分文件的抓取  >Xxi2Vy  
**FileSplitterFetch.java SjvSnb_3  
*/ dfXBgsc6i  
package NetFox; :\%ZTBLL  
(b7',:_U7  
iz27yXHZ~  
import java.io.*; ziv*4  
import java.net.*; e8k|%m<Sp  
PD-*rG `  
;/!o0:m^I  
public class FileSplitterFetch extends Thread { 3E!3kSh|  
pzT`.#N:M  
d}@n,3  
String sURL; //File URL @CKMJ^#|  
long nStartPos; //File Snippet Start Position q( %)^C  
long nEndPos; //File Snippet End Position ?',GRaD  
int nThreadID; //Thread's ID !fJy7Y  
boolean bDownOver = false; //Downing is over , Q)  
boolean bStop = false; //Stop identical x}uDW   
FileAccessI fileAccessI = null; //File Access interface $ou/ Fn  
e1ExB#  
$NBQv6#:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~pwk[Q!  
{ ;S'1fci6  
this.sURL = sURL; x}OJ~Yk]  
this.nStartPos = nStart; NOl/y@#  
this.nEndPos = nEnd; E=ObfN"ge  
nThreadID = id; $|I hO  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r%`3*<ALV)  
} p &i+i  
MSe >1L2=  
AH^ud*3F  
public void run() IB^vEY!`6_  
{ S)`@)sr  
while(nStartPos < nEndPos && !bStop) qCm8R@  
{ VwT&A9&{8  
.RWq!Z=)3  
FaKZ|~Y e  
try{ <'~6L#>,<  
URL url = new URL(sURL); "7w=LhzV[$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?v&2^d4C*F  
httpConnection.setRequestProperty("User-Agent","NetFox"); -gv[u,R  
String sProperty = "bytes="+nStartPos+"-"; LRSt >; M  
httpConnection.setRequestProperty("RANGE",sProperty); L#N ]1#;  
Utility.log(sProperty); lN*"?%<x>  
+^[SXI^JaJ  
5-:H  
InputStream input = httpConnection.getInputStream(); `~ h8D9G  
//logResponseHead(httpConnection); ov1#BeQ  
ob9=/ R?i  
Xv xrz{  
byte[] b = new byte[1024]; ,v#3A7"yW  
int nRead; b:$q5  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UGP&&A#T-  
{ it->)?"(6  
nStartPos += fileAccessI.write(b,0,nRead); b6@0?_n  
//if(nThreadID == 1) %z-n2%  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w=[ITQ|W%  
} Wli!s~c5Fo  
m(CsO|pz  
(w Q,($@  
Utility.log("Thread " + nThreadID + " is over!"); L8KaK  
bDownOver = true; CUj$ <ay=  
//nPos = fileAccessI.write (b,0,nRead); u|(Iu}sE=  
} b\H,+|i K  
catch(Exception e){e.printStackTrace ();} J4?SC+\  
} xj JoWB  
} VI)hA ^ S  
SU(J  
xN6}4JB  
//打印回应的头信息 fbkAu  
public void logResponseHead(HttpURLConnection con) f 2k~(@!h  
{ DKG; up0  
for(int i=1;;i++) Zk5AZ R!|  
{ 6dYa07  
String header=con.getHeaderFieldKey(i); iAXF;'|W  
if(header!=null) 0<nW nD,z  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tZ:fh  p  
Utility.log(header+" : "+con.getHeaderField(header)); z\Z+>A  
else 2c3/iYCKP  
break; WmE4TL^8?  
} AA}+37@2I  
} n`p/;D=?  
bUc ++M  
hPt=j{aJ%<  
public void splitterStop() ^CB@4$!   
{ iN2591S  
bStop = true; ucUu hS5  
} #_zj5B38E  
jIWX6  
y 48zsm{  
} /Ur]U w  
Rj-4K@a8#N  
^O**ZndB/  
/* r<'B\.#tp>  
**FileAccess.java %< Jj[F  
*//文件访问(定位,写) %/R[cj 8  
package NetFox; /.(F\2+A  
import java.io.*; F mQiy+.|  
QG09=GQ  
@`HW0Y_:  
public class FileAccessI implements Serializable{ aQV?}  
X&!($*/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6`5DR~  
RandomAccessFile oSavedFile; QV _a M2  
long nPos; _w7yfZLv+  
h-\+# .YP  
*?o 'sTH  
public FileAccessI() throws IOException %%lJyLq'Vk  
{ 9dp1NjOtAc  
this("",0); #YSFiy:+r_  
} }jYVB|2  
isz-MP$:K5  
{-yw@Kq  
public FileAccessI(String sName,long nPos) throws IOException YyC$\HH6  
{ "}:SXAZ5`  
oSavedFile = new RandomAccessFile(sName,"rw"); !)FKF7'  
this.nPos = nPos; m2Wi "X(I_  
oSavedFile.seek(nPos); J?f7!F:8  
} :v^OdW  
/Y| <0tq  
zn5|ewl@"  
public synchronized int write(byte[] b,int nStart,int nLen) hdYd2 j  
{ YH&0Vy#c$  
int n = -1; D*ZswHT{y  
try{ "1hFx=W+\  
oSavedFile.write(b,nStart,nLen); 'w_Qs~6~{  
n = nLen; P@U2Q%\  
} l$C Y gm  
catch(IOException e) *Q;?p hr  
{ Y\E7nll:.  
e.printStackTrace (); ~FnY'F<35  
} ;V84Dy#b  
 `dIwBfg_  
aO* v"^oF  
return n; KuMH,rXF  
} n{"a 0O  
l <yYfGO  
Oki{)Ssy  
} "fu@2y4^  
I~,bZA  
TmJXkR.5  
/* fj[Kbo 7!h  
**SiteInfoBean.java M} Mgz  
*/ Zl?9ibm;@  
package NetFox; , jCE hb  
kk}_AZ0eK  
l_P90zm39!  
public class SiteInfoBean { U"L-1]L  
BxB B](  
zEw~t&:e  
private String sSiteURL; //Site's URL Sp[]vm8N  
private String sFilePath; //Saved File's Path Cw~fP[5XMF  
private String sFileName; //Saved File's Name t_\&LMD  
private int nSplitter; //Count of Splited Downloading File H"wIa8A  
 Rp6q)  
=|H.r9-PK6  
public SiteInfoBean() V2$M`|E  
{//nSplitter的缺省值为5 '|G8yojz  
//default value of nSplitter is 5 [x -<O:r=P  
this("","","",5); {N@Pk[!  
} G}@a]EGm  
)g`~,3G  
~Sx\>wBlc  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6ck%M#v  
{ 6u{%jSA>D\  
sSiteURL= sURL; ]6,D 9^{;  
sFilePath = sPath; 3]kN9n{  
sFileName = sName; ;dTxQ_:  
this.nSplitter = nSpiltter; bl#6B.*=  
%Hu.FS5'  
#j"GS/y"  
} v(P <_}G  
m1M6N`f  
6+:;M b_S  
public String getSSiteURL() 593!;2/@  
{ ,Uy;jk  
return sSiteURL; rnBp2'EM  
} 3Qu-X\  
T[2<_nn=  
sk@aOv'*(  
public void setSSiteURL(String value) d"thM  
{ nY,LQ0r  
sSiteURL = value; |Gr@Mi5  
} o 80x@ &A:  
{HjJ9ZGQ  
c!mMH~#  
public String getSFilePath() WnA Y<hZ|  
{ N3w y][bo  
return sFilePath; hz5t/E  
} 2%) ~E50U  
 gOy{ RE  
o Va[  
public void setSFilePath(String value) bl\;*.s'  
{ :bXTV?#0  
sFilePath = value; t|*UlTLm  
} G^#? ~  
[C@ Ro,mI  
\p!m/2  
public String getSFileName() l|M|;5TW  
{ }Ggn2 X  
return sFileName; -jVg {f!  
} $_gv(&ZT  
iDYm4sY  
M%s!qC+  
public void setSFileName(String value) )/Oldyp  
{ gl!ht@;>ak  
sFileName = value; {~#d_!(  
} =nlj|S ~3  
^cuH\&&7  
/'^ BH A|h  
public int getNSplitter() "tu*(>'~5  
{ W!1 B~NH#  
return nSplitter; k7M{+X6[  
} 7**zO3 H  
::@JL  
J!}R>mR  
public void setNSplitter(int nCount) ajX] ui  
{ #hXuGBZEI  
nSplitter = nCount; !04 ^E  
} }&%&0$%  
} |*L/ m0'L  
845\u&  
&iT^IkA{  
/* &uI33=   
**Utility.java ER:K^ Za  
*/ (U:6vk3Q  
package NetFox; >E WK cocM  
3M>y.MS  
milQxSpj  
public class Utility { 1 /SB[[g  
GE\({V.W  
1U ='"  
public Utility() ~eUv.I/  
{ ^c| 0?EH  
m~F ~9&  
0\+$j5;  
} c$_}   
4x.I"eW~&  
//线程睡眠 lE3&8~2   
public static void sleep(int nSecond) 7r pTk&`  
{ sR| /s3;  
try{ 7>-99o^W  
Thread.sleep(nSecond); l s%'\}  
} 6L2Wv5C  
catch(Exception e) i'}"5O+  
{ 2SKtdiY  
e.printStackTrace (); ;`Z>^.CB  
} B9'2$s+Z;  
} S}K-\[i?  
'Y/8gD~.  
//日志 .[Ny(X/]/}  
public static void log(String sMsg) Gz7,g Y  
{ &+/$~@OK  
System.err.println(sMsg); Zm#,Ike?#  
} '@"A{mrE  
<XzRRCYQ  
='(;!3ZH  
public static void log(int sMsg) EpENhC0  
{ vb`:   
System.err.println(sMsg); /}s#   
} '(8} <(%  
} ryTtGx%a  
l{V(Y$xp3  
V_KHVul  
/* X$ A ]7t  
**TestMethod.java =HMuAUa.  
*/ YW"nPZNPy~  
package NetFox; nDNK}O~'  
'f6!a5qC  
O\w-hk  
public class TestMethod { bLUyZ3m!  
<O{G&  
6lwWFR+k  
public TestMethod() VGOdJ|2]Wr  
{ ///xx/weblogic60b2_win.exe 8,:lw3x1  
try{ %gTY7LIe1z  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pzU:AUW  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'JAe =K H  
SiteFileFetch fileFetch = new SiteFileFetch(bean); >8injW3 52  
fileFetch.start(); "p&4Sn3T2?  
} Dj w#{WR  
catch(Exception e){e.printStackTrace ();} W;8}`k  
s_6Iz^]I  
H#QPcp@  
} GGFrV8  
Z FIgKWZ'  
7Ur'@wr  
public static void main(String[] args) {tnhP^C3>  
{ :kucDQE({?  
new TestMethod(); Qq\hD@Z|  
} U"K%ip:Wd  
} +b{tk=Q:  
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:
3+5=?,请输入中文答案:八 正确答案:八