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
  • 9144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
/* Pu*st=KGB  
**SiteFileFetch.java auGt>,Zj\Q  
*/ Ex*g>~e  
package NetFox; z?7s'2w&{  
import java.io.*; otPEJ^W&  
import java.net.*; [NKWudq  
Cg&1  
_Juhl^LM;  
public class SiteFileFetch extends Thread { M{(Y|3W  
}D=h"\_=  
~" $9auQtC  
SiteInfoBean siteInfoBean = null; //文件信息Bean tv;3~Y0i  
long[] nStartPos; //开始位置 4/d#)6  
long[] nEndPos; //结束位置 }B]FHpi  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 >U) ,^H(  
long nFileLength; //文件长度 {'vvE3iZ  
boolean bFirst = true; //是否第一次取文件 Lnj5EY er  
boolean bStop = false; //停止标志 q#WqU8~Y  
File tmpFile; //文件下载的临时信息 *Pq`~W_M7  
DataOutputStream output; //输出到文件的输出流 0,/[r/=jT  
Q!|71{5U  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) >>!+Ri\@  
public SiteFileFetch(SiteInfoBean bean) throws IOException r+Z+x{  
{ ! q1Ql18n  
siteInfoBean = bean; Xt~/8)&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); "Dy&`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Bq2}nDP  
if(tmpFile.exists ()) :x;D- kZ  
{ 5aWKyXBIx  
bFirst = false; PH=wP ft  
read_nPos(); t8^*s<O  
} Y#N'bvE|%  
else f,?7,?x  
{ RGxOb  
nStartPos = new long[bean.getNSplitter()]; "<.b=mN-  
nEndPos = new long[bean.getNSplitter()]; =+"XV8Fi,  
} %? iE3j!q  
6!gGWn5>}  
dkVVvK  
_p~ `nQ=7  
} CiMN J  
@{$SjR8Q $  
AM}OL Hj  
public void run() 3Y r   
{ h7Ma`w\-  
//获得文件长度 'i@Y #F%D  
//分割文件 Q.8Jgel1  
//实例FileSplitterFetch x,1&ml5  
//启动FileSplitterFetch线程 .II'W3Fr  
//等待子线程返回 %Ajf|Go0/G  
try{ "+AeqrYYm5  
if(bFirst) t Y^:C[  
{ qI'a|p4fn?  
nFileLength = getFileSize(); !}vz_6)  
if(nFileLength == -1) QR,i b  
{ ?}Mv5SO  
System.err.println("File Length is not known!"); u{_T,k<!  
} KT|$vw2b  
else if(nFileLength == -2) G N{.R7  
{ T8RQM1D_s  
System.err.println("File is not access!"); zU}0AVlIL:  
} XCt}>/"s\h  
else h<QXr'4+  
{ bGSgph  
for(int i=0;i<nStartPos.length;i++) ~o8$/%Oeb/  
{ HAU8H'h  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _=cMa's  
} 'Y-c*q  
for(int i=0;i<nEndPos.length-1;i++) M2m@N-+R   
{ \C>I6{  
nEndPos = nStartPos[i+1]; )X7ZX#ttH  
} 5ax/jd~}  
nEndPos[nEndPos.length-1] = nFileLength; .vb*|So  
} $QY(7Z"  
} &KD m5p  
OgzPX^q/=  
.+8w\>w6g  
//启动子线程 gFW1Nm_DJ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {j(,Q qB;f  
for(int i=0;i<nStartPos.length;i++) k!! o!rBS  
{ `5gcc7b  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y6Rg@L&U  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sF}E =lY  
nStartPos,nEndPos,i); a{{([uZ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ho0T$hB  
fileSplitterFetch.start(); !e%#Zb MIo  
} Kj}}O2  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), le1'r>E$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /*8"S mte  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", he!e~5<@y  
nEndPos = " + nFileLength); Ok,hm.|  
// fileSplitterFetch[nPos.length-1].start(); 6 .*=1P*?  
udw5A*Ls  
PvO>}(=  
//等待子线程结束 j:fL_1m  
//int count = 0; bhFzu[B  
//是否结束while循环 -\r*D#aHBN  
boolean breakWhile = false; qf'uXH  
O1-Ne.$  
l3.HL> o  
while(!bStop) 4s3n|6v  
{ 7gv kd+-*  
write_nPos(); #LcF;1o%o2  
Utility.sleep(500); \N!k)6\  
breakWhile = true; =0O`VSb  
6Si z9  
]ul]L R%.  
for(int i=0;i<nStartPos.length;i++) !d^5mati)T  
{ `L0}^ |`9  
if(!fileSplitterFetch.bDownOver) QQ pe.oF  
{ S3.Pqp_<  
breakWhile = false; rrmr#a  
break; w+[r$+z!k  
} T?Hs_u{  
} [NyR$yD{  
if(breakWhile) l'mgjv~  
break; e6,/ i  
mKn:EqA  
8 \%*4L'  
//count++; m+,a=sR  
//if(count>4) f%d7?<rw  
// siteStop(); 3~"G27,  
} +Z /Pj_.o  
D/Bb)]9I  
LzP+l>m  
System.err.println("文件下载结束!"); l2._Z Py  
} B`9'COw  
catch(Exception e){e.printStackTrace ();} O cd ^{u  
} 4IIe1 .{  
O~trv,?)  
6 [w_ /X"  
//获得文件长度 6-j><'  
public long getFileSize() K+2<{qwh  
{ x^xlH!Sc  
int nFileLength = -1; 0LeR#l:I  
try{ auK*\Wjm?  
URL url = new URL(siteInfoBean.getSSiteURL()); w+z~Mz}Vz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _e7 Y R+  
httpConnection.setRequestProperty("User-Agent","NetFox"); `[X5mEe  
w<*6pP y  
<$qe2Ft Uq  
int responseCode=httpConnection.getResponseCode(); y)CnH4{  
if(responseCode>=400) NirG99kyo  
{ sWa`-gc  
processErrorCode(responseCode); Z vM~]8m  
return -2; //-2 represent access is error XE6sFU  
} aHuZzYQ*"j  
ER;?[!  
g\ilK:r}  
String sHeader; Hyh$-iCa  
)7f;FWI  
3"!h+dXw  
for(int i=1;;i++) `O/1aW1  
{ )O;6S$z9Y  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y HSdaocp  
//Utility.log(in.readLine()); =ss(~[  
sHeader=httpConnection.getHeaderFieldKey(i); KP,#x$Bg  
if(sHeader!=null) J2W#vFe\  
{ bvzNur_  
if(sHeader.equals("Content-Length")) THEpW{.E  
{ %{Ib  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }M7{~ov#s  
break; (#KSwWo{ed  
} O*jTrZ(k  
} UNY O P{  
else wIeF(}VM  
break; 8~* |muN.e  
} ,6@s N'c  
} >h)D~U(H  
catch(IOException e){e.printStackTrace ();} eO%w i.Q  
catch(Exception e){e.printStackTrace ();} *62Cf[a  
6Uh_&?\%  
[L(qrAQ2|z  
Utility.log(nFileLength); [A\DuJx  
)IBvm1  
BLaF++Fop  
return nFileLength; 8/gA]I 6=#  
} }ZqnsLu[)  
l/xpAx  
@qUgp*+{  
//保存下载信息(文件指针位置) T"IDCT'z  
private void write_nPos() )>"|<h.2]  
{ {3Y R_^>?  
try{ 7! sR%h5p  
output = new DataOutputStream(new FileOutputStream(tmpFile)); emT/5'y  
output.writeInt(nStartPos.length); #|j8vmfn$e  
for(int i=0;i<nStartPos.length;i++) W79Sz}):  
{ 2^w8J w9  
// output.writeLong(nPos); WQiIS0BJ *  
output.writeLong(fileSplitterFetch.nStartPos); 3QhQpPk) ,  
output.writeLong(fileSplitterFetch.nEndPos); p!/!ZIo  
} .~ O- <P#  
output.close(); u(W>HVEG  
} |1%eo.  
catch(IOException e){e.printStackTrace ();} .+) AeGh  
catch(Exception e){e.printStackTrace ();} ^#gJf*'UE  
} =|LB,REN  
J.(mg D  
)ko[_OJj  
//读取保存的下载信息(文件指针位置) XOL_vS24  
private void read_nPos() kxCN0e#_  
{ `T,^os#6  
try{ ]bP1gV(b-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oM^VtH=>  
int nCount = input.readInt(); Ua.%?V  
nStartPos = new long[nCount]; j4wsDtmAU  
nEndPos = new long[nCount]; U<|*V5   
for(int i=0;i<nStartPos.length;i++) sK@]|9ciQ  
{ $Sgq7  
nStartPos = input.readLong(); 3~%M4(  
nEndPos = input.readLong(); MK.TBv  
} 7Y.mp9,  
input.close(); yZ-Ql1 1  
} Y41b8.|P+  
catch(IOException e){e.printStackTrace ();} : #OaE,  
catch(Exception e){e.printStackTrace ();} T@xaa\bzg  
} #AH gY.  
Ca["tks  
o'_eLp  
private void processErrorCode(int nErrorCode)  c?*x2Vk  
{ *P\OP'o_  
System.err.println("Error Code : " + nErrorCode); }XD=N#p@z  
} *7{{z%5Pu  
W0S\g#  
4N)45@jk[  
//停止文件下载 zmg :Z p=  
public void siteStop() 06 an(& a9  
{ +^q- v-  
bStop = true; 7O~hA*Z  
for(int i=0;i<nStartPos.length;i++) ZEB,Q~  
fileSplitterFetch.splitterStop(); by$S#e f  
Lh-+i  
ikb;,Js  
} PKZMuEEy,  
} IN@ =UAc&  
//负责部分文件的抓取 3F9dr@I.7  
**FileSplitterFetch.java K_Kz8qV.?  
*/ 4|hfzCjMI  
package NetFox; })?KpYk  
|[@v+koq  
),@m 3wQ  
import java.io.*; &r!jjT  
import java.net.*; C_ W%]8u  
8#|PJc  
t; @T~%  
public class FileSplitterFetch extends Thread { ${tBu#$-d  
{tuGkRY2 ~  
acI%fYw5p`  
String sURL; //File URL _o-01gu.  
long nStartPos; //File Snippet Start Position h`D+NZtWm  
long nEndPos; //File Snippet End Position t?FPmbj v  
int nThreadID; //Thread's ID yG<Q t+D  
boolean bDownOver = false; //Downing is over iwfH~  
boolean bStop = false; //Stop identical ~,{nBp9*  
FileAccessI fileAccessI = null; //File Access interface qJK6S4O]  
|iVw7M:  
m,SWG[~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i+|/V&#3[  
{ mW#p&{  
this.sURL = sURL; uXdR-@80*  
this.nStartPos = nStart; Lmc"q FzK  
this.nEndPos = nEnd; -V52?Hq  
nThreadID = id; #Qd"d3QG  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WE&"W$0  
} {+ WI>3  
9U!#Y%*T  
41o ~5:&  
public void run() ~GjM:*  
{ H?j}!JzAC  
while(nStartPos < nEndPos && !bStop) E>rWm_G  
{ *%QTv3{  
T0BM:ofx  
SI;SnF'[7  
try{ (L"G,l  
URL url = new URL(sURL); k^\>=JTq=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ] dHV^!  
httpConnection.setRequestProperty("User-Agent","NetFox"); ea!Znld]  
String sProperty = "bytes="+nStartPos+"-"; R1\$}ep^  
httpConnection.setRequestProperty("RANGE",sProperty); 0^3@>> ^  
Utility.log(sProperty); K[i|OZWu  
R^GLATM  
u )KtvC!  
InputStream input = httpConnection.getInputStream(); %I;iP|/  
//logResponseHead(httpConnection); 'q{|p+  
G8F43!<  
9h'klaE(  
byte[] b = new byte[1024]; Z#|IMmT;*=  
int nRead; qjd8Q  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q/t~`pH3  
{ G1:2MPH  
nStartPos += fileAccessI.write(b,0,nRead); T\o!^|8  
//if(nThreadID == 1) ahm@ +/2  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9h 0^_|"  
} vq*)2.  
hh"=|c  
,a?$F1Z-  
Utility.log("Thread " + nThreadID + " is over!"); dtUt2r)6L;  
bDownOver = true; OcGHMGdn  
//nPos = fileAccessI.write (b,0,nRead); )qx,>PL  
} [lX3":)  
catch(Exception e){e.printStackTrace ();} -4'yC_8t  
} cakb.Q  
} ~85Pgb<  
7nL3+Pq  
jaI mO  
//打印回应的头信息 tL~?)2uEN  
public void logResponseHead(HttpURLConnection con) @}@J$ g  
{ #35@YMF  
for(int i=1;;i++) Um9]X@z  
{ ? $LKn2C  
String header=con.getHeaderFieldKey(i); b_T?jCyW  
if(header!=null) +yd(t}H@  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h_:|H8t;w  
Utility.log(header+" : "+con.getHeaderField(header)); pg'3j3JW$  
else ?H_'L4Wv  
break; B!cg)Y?.bd  
} Y l1sAf/  
} pu +"bq  
S<V__Sv  
9@."Y>1G  
public void splitterStop() , 1{)B  
{ -5 YvtL  
bStop = true; idr,s\$>  
} *n=NBkq%/!  
UR&Uwa&.  
l[q%1-N  
} a}+7MEUmZ/  
tj_+0J$sw:  
d8? }69:h  
/* V_g9oR_  
**FileAccess.java YkKq}DXj  
*//文件访问(定位,写) '<C I^5^  
package NetFox; wcT0XXh  
import java.io.*; tGs=08`  
t$z FsFTQ  
uwl;(zwh_  
public class FileAccessI implements Serializable{ U'st\Dt  
]&3UF?  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4 }l,F  
RandomAccessFile oSavedFile; =yf LqU  
long nPos; K>TdN+Z}=  
`V@{#+X  
"mnWqRpX  
public FileAccessI() throws IOException rlvo&(a  
{ hN6j5.x%  
this("",0); tVZj tGz=  
} h,q%MZ==^s  
E lt=/,v`!  
JU7EC~7|2c  
public FileAccessI(String sName,long nPos) throws IOException {ZH9W  
{ i!jZZj-{  
oSavedFile = new RandomAccessFile(sName,"rw"); Ch`XwLY9  
this.nPos = nPos; Z~t OR{q  
oSavedFile.seek(nPos); Yw=Ve 0  
} w<*tbq  
1pC!F ;9Oo  
n^|n6(EZ  
public synchronized int write(byte[] b,int nStart,int nLen) adh=Kp e!w  
{ s% "MaDz  
int n = -1; :luVsQ  
try{ 8 kw`=wSH>  
oSavedFile.write(b,nStart,nLen); bE2^sx`(  
n = nLen; DD\:glo  
} " z\T$/  
catch(IOException e) @X_x?N  
{ EZz Ox(g  
e.printStackTrace (); udDhJ?  
} k+2~=#  
lvIKL!;H  
"w0>  
return n; sn&y;Vc[$  
} P=eVp(/x  
F_=RY ]  
 4G&E?  
} ja}_u}:  
l;: L0(('  
Z9s tB>?  
/* U7.3`qd"  
**SiteInfoBean.java <Brq7:n|  
*/ 5Ya TE<G  
package NetFox; PD12gUU?  
BEyg 63=  
U[=VW0  
public class SiteInfoBean { z%;b-PpS  
- *!R  
}<o.VY&;.  
private String sSiteURL; //Site's URL m(E-?VMHo  
private String sFilePath; //Saved File's Path s_ -G`xT>{  
private String sFileName; //Saved File's Name 1+RG@Cp  
private int nSplitter; //Count of Splited Downloading File D(D:/L8T,  
5BCXI8Ox9x  
[f}YXQ0N)  
public SiteInfoBean() *{8K b>D  
{//nSplitter的缺省值为5 "qUUH4mR`  
//default value of nSplitter is 5 ('pNAn!]  
this("","","",5); eKNZ?!c=  
} ~;k-/Z"  
^AK<]r<?L?  
H#x=eDU|k  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HDZB)'I  
{ oCdWf63D  
sSiteURL= sURL; "5u*C#T2$  
sFilePath = sPath; 5 G cdz  
sFileName = sName; -?`^^ v  
this.nSplitter = nSpiltter; "Q6oPDX(  
+uKh]RP  
$^?"/;8P5  
} S\K;h/;V  
lN#W  
0P^RciC f  
public String getSSiteURL() 0Lmq?D  
{ Esvr~)Y  
return sSiteURL; %719h>$  
} TJ8IYo| D  
.'JO7of  
Y%y=  
public void setSSiteURL(String value) j'FSd*5m  
{ a]-F,MJ  
sSiteURL = value; ec+&K?T  
} %!I7tR#;  
?U.+SQ  
awh<CmcZ  
public String getSFilePath() E|Mu1I]e  
{ {J;[ Hf5  
return sFilePath; 3:Q5dr+1_  
} ^.)oQo SE  
rpH ,c[D  
$q,2VH:Ip  
public void setSFilePath(String value) (CFm6p'RZ  
{ *Z\B9mx  
sFilePath = value; 2\80S[f  
} P}hHx<L  
AL@8v=  
o0nd]"q?  
public String getSFileName() dPZrX{ c  
{ S?ELFq(g  
return sFileName; !m8MyZ}%  
} 4FUY1p  
y(/"DUx  
EYWRTh  
public void setSFileName(String value) @=JOAo  
{ KBJ%$OQV  
sFileName = value; `&y Qtj# '  
} 2GeJ\1k  
>tc#Ofgzd  
|j:"n3~6  
public int getNSplitter() B!{vSBq  
{ nk=+6r6  
return nSplitter; FyleK+D?  
} !YX$4_I  
lz1RAp0R "  
}#%3y&7M7  
public void setNSplitter(int nCount) I!sh+e  
{ @GTkS!86  
nSplitter = nCount; G*;?&;*  
} t<=Ru*p  
} 4z6i{n-k  
N8*6sK.  
b,C2(?hg  
/* 0Va+l)F  
**Utility.java AzFd#P  
*/ 3XykIj1  
package NetFox; aE aU_f /  
3an9Rb V  
1,Ams  
public class Utility { .+ezcG4q  
jGm`Qg{<  
4)Jtc2z7Z\  
public Utility() )ZZjuFQJ)  
{ oVZI ([O  
8M6 Xd]{%  
GK6/S_l%D+  
} stxei 6  
3{:AG,G  
//线程睡眠 /H (55^EMZ  
public static void sleep(int nSecond) ;*{"|l qe  
{  ujin+;1  
try{ 1s-dqHz"s  
Thread.sleep(nSecond); 8NF93tqD6  
}  lL\%eQ  
catch(Exception e) 1>yh`Bp\=  
{ I8x,8}o>V  
e.printStackTrace (); lIhP\:;S&  
} Aj{c s  
} Yamu"#  
#}xw *)3  
//日志 7y?aw`Sw:  
public static void log(String sMsg) ^5'pJ/BV  
{ CE5A^,EsB  
System.err.println(sMsg); ']bw37_U,  
} #zf,%IYF  
:  I q  
qkbGM-H%U  
public static void log(int sMsg) 8NZQTRdH  
{ #}p@+rkg2  
System.err.println(sMsg);  Y+d+  
} C ^IPddw>  
} fEo5j`}  
u~xfI[8C  
\; voBU  
/* &wa2MNCG8  
**TestMethod.java \<aR^Sj.  
*/ ]5O]=^ u0  
package NetFox; ~dBx<  
+$YH dgZ.  
41v#|%\w  
public class TestMethod { Q2>o+G  
Z35(f0b  
#b eLo J  
public TestMethod() J))U YJO  
{ ///xx/weblogic60b2_win.exe 'NNfzh  
try{ *Y':raP  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +;ylld  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ym8pB7E7%  
SiteFileFetch fileFetch = new SiteFileFetch(bean); G,}"}v:  
fileFetch.start(); 7'!DK;=TD6  
} *{("T  
catch(Exception e){e.printStackTrace ();} +>ld  
h e[2,  
sOO_J!bblP  
} 8AJ#].q0F  
S}P rgw/  
$x*(D|\'<  
public static void main(String[] args) W6s-epsRmT  
{ LP'wL6#  
new TestMethod(); mpNS}n6  
} mndKUI}d  
} 6~-,.{Y  
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