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
  • 7952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
/* &W+G{W{3  
**SiteFileFetch.java xKST-:c+  
*/ ptyDv  
package NetFox; H)T# R?  
import java.io.*; S\g7wXH  
import java.net.*; BON""yIC   
!9LAXM  
F>kn:I"X)  
public class SiteFileFetch extends Thread { +1jqCW  
RK:sQWG  
8sF0]J[g{  
SiteInfoBean siteInfoBean = null; //文件信息Bean ;To+,`?E;q  
long[] nStartPos; //开始位置 @-@rG>y^:  
long[] nEndPos; //结束位置 h;UdwmT  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 yn ":!4U1  
long nFileLength; //文件长度 LY!3u0PnlT  
boolean bFirst = true; //是否第一次取文件 ; 9&.QR(  
boolean bStop = false; //停止标志 9Q7cUoxY  
File tmpFile; //文件下载的临时信息 OGi4m |  
DataOutputStream output; //输出到文件的输出流 | ,l=v`/  
bA^: p3  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) W<N QU f[=  
public SiteFileFetch(SiteInfoBean bean) throws IOException H&=4y) /.  
{ p z+}7  
siteInfoBean = bean; 4i\aW:_'i  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); }:l%,DBw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 5YG@[ic  
if(tmpFile.exists ()) $4*E\G8  
{ C+]q  
bFirst = false; pF*~)e  
read_nPos(); UH,4b`b  
} +fCyR  
else !na0Y  
{ hOLy*%  
nStartPos = new long[bean.getNSplitter()]; 2X;0z$  
nEndPos = new long[bean.getNSplitter()]; y#Za|nt  
} &T/q0bwd  
^_S-s\DW  
K6yFpVl  
UNcJ=   
} Ysc|kxLb  
O{cGk: y  
g yH7((#i  
public void run() ;/^]|  
{ - Zoo)  
//获得文件长度 t k/K0u  
//分割文件 ]7R&m)16  
//实例FileSplitterFetch GE8D3V;*V  
//启动FileSplitterFetch线程 I%Po/+|+  
//等待子线程返回 b}?@syy8  
try{ < J<;?%]  
if(bFirst) 0m YZ7S5g  
{ o`T<}z26  
nFileLength = getFileSize(); yw Q!9 \  
if(nFileLength == -1) 8&A|)ur4  
{ 3|'#n[3  
System.err.println("File Length is not known!"); 07LL)v~  
} W/ZahPPq  
else if(nFileLength == -2) > ?{iv1  
{ N7HbOLpM  
System.err.println("File is not access!"); Vh.;p.!e  
} OxHw1k  
else ;GgQ@s@  
{ 2*FWIHyf  
for(int i=0;i<nStartPos.length;i++) u388Wj   
{ gQpD]p%k  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); mA] 84zO  
} zEPx  
for(int i=0;i<nEndPos.length-1;i++) z1SMQLk  
{ rb}wv16?  
nEndPos = nStartPos[i+1]; 23\j1?  
} l;{N/cS  
nEndPos[nEndPos.length-1] = nFileLength; NtA|#"^  
} ZG \ I1  
} z Jo#3  
e"s{_V  
w{zJE]7  
//启动子线程 q{De&Bu  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; " ,aT<lw.  
for(int i=0;i<nStartPos.length;i++) qp~4KukL  
{ 1nlE3Y?AV  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sRe#{EuJ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q!2iOvK  
nStartPos,nEndPos,i); AR+\uD=\I-  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s?G'l=CcKu  
fileSplitterFetch.start(); sAjKf\][  
} 5nxS+`Pn.)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N9JgV,`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \BbOljM=  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XC/]u%n8](  
nEndPos = " + nFileLength); ?;r8SowZ7  
// fileSplitterFetch[nPos.length-1].start(); LcpyW=)}"V  
%M;_(jda  
\A3>c|  
//等待子线程结束 x(3 I?#kE  
//int count = 0; THbtu*El  
//是否结束while循环 32bkouq  
boolean breakWhile = false; Gkodk[VuLs  
pT ocqJ22  
:9x084ESR)  
while(!bStop) `3sy>GU?  
{ RZ<+AX9R  
write_nPos(); %+7T9>+  
Utility.sleep(500); Vr/` \441  
breakWhile = true; UP~WP@0F  
1hMX(N&|  
cpF1XpvT  
for(int i=0;i<nStartPos.length;i++) -|k&L}\OB0  
{ CNpe8M=/3  
if(!fileSplitterFetch.bDownOver) HV$9b~(  
{ .^W\OJ`G  
breakWhile = false; (Xr_ np @  
break; y[^k*,= 9  
} /50g3?X,  
} ;5Wx$Yfx  
if(breakWhile) az \<sWb#  
break; S-M)MCL  
!}L~@[v,uL  
aX[1H6&=7  
//count++; x '=3&vc4  
//if(count>4) $xUzFLh=`  
// siteStop(); #A|D\IhF  
} )4'x7Qg/  
M~ i+F0  
Q2[prrk%j  
System.err.println("文件下载结束!"); k binf  
} :p\(y  
catch(Exception e){e.printStackTrace ();} ,{uW8L  
} 6HEqm>Yau  
d Y:|Ef|v(  
U=&^H!LVY  
//获得文件长度 ]8xc?*i8  
public long getFileSize() c4ZuW_&:  
{ T<TcV9vM  
int nFileLength = -1; _X,[]+ziu%  
try{ /slm ]'  
URL url = new URL(siteInfoBean.getSSiteURL()); *gM,x4Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EI=Naq  
httpConnection.setRequestProperty("User-Agent","NetFox"); V>FT~k_"  
O2`oe4."vd  
JGk3 b=K  
int responseCode=httpConnection.getResponseCode(); f.aB?\"f6  
if(responseCode>=400) Uw2,o|=O  
{ |b$>68:  
processErrorCode(responseCode); $S6HZG:N  
return -2; //-2 represent access is error }XGMa?WR  
} Z{,GZT  
3wN?|N  
Yo~LckFF  
String sHeader; n) _dH/"  
;t;Y.*&=S  
)h>\05|T  
for(int i=1;;i++) Z>(r9 R3{  
{ z.2r@Psk  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -y&v9OC2-  
//Utility.log(in.readLine()); E ;BPN  
sHeader=httpConnection.getHeaderFieldKey(i); sJ))<,e5I  
if(sHeader!=null) _KB{J7bs<a  
{ V>b2b5QAH,  
if(sHeader.equals("Content-Length")) Ow cVPu_  
{ '%zN  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D00G1:Ft(T  
break; ^wx%CdFm'P  
} r/NSD$-n  
} [x2JFS#4  
else ia%z+:G  
break; @uI?  
} F_A%8)N  
} h4hN1<ky\  
catch(IOException e){e.printStackTrace ();} j[ J 5y#  
catch(Exception e){e.printStackTrace ();} YG0PxZmi  
7|&e[@B  
X,C*qw@  
Utility.log(nFileLength); :]P~.PD5,  
_BZ1Vnv  
!_CX2|  
return nFileLength; kz ZDtI)  
} S  ~@r  
{]wIM^$6+  
O1GDugZ  
//保存下载信息(文件指针位置) '|vD/Qf=&  
private void write_nPos() Tub1S v>J  
{ "w}-?:# j  
try{ f4]N0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Nls83 W  
output.writeInt(nStartPos.length); E,{GU  
for(int i=0;i<nStartPos.length;i++) {>8Pl2J  
{ )y9;OA  
// output.writeLong(nPos); Y/. AUN Z  
output.writeLong(fileSplitterFetch.nStartPos); NH7`5mF$  
output.writeLong(fileSplitterFetch.nEndPos); A /q2g7My  
} yJ!OsD  
output.close(); Z[",$Lt  
} 21r= = H$  
catch(IOException e){e.printStackTrace ();} T vrk^!  
catch(Exception e){e.printStackTrace ();} 2O eshkE  
} K(<$.  
' |&>/dyq  
"-w ^D!C  
//读取保存的下载信息(文件指针位置) #SKfE  
private void read_nPos() Og,Y)a;=  
{ K&=D-50%  
try{ KAd_zkUA  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +7,8w  
int nCount = input.readInt(); Zy^=fM  
nStartPos = new long[nCount]; DH 6q7"@  
nEndPos = new long[nCount];  n;wwMMBM  
for(int i=0;i<nStartPos.length;i++) I*EJHBsQ5  
{ Q,{^S,s<   
nStartPos = input.readLong(); RFw(]o,9cR  
nEndPos = input.readLong(); ,4[dLWU  
} 4&Byl85q  
input.close(); k`Nyi )AGe  
} b"I~_CL|  
catch(IOException e){e.printStackTrace ();} LO)GTyzvJ  
catch(Exception e){e.printStackTrace ();} {Fbg]'FQ  
} ]eE 1n2  
]kx-,M(  
#~L!pKM  
private void processErrorCode(int nErrorCode) ;HDZ+B  
{ "'m)VG  
System.err.println("Error Code : " + nErrorCode); 2 P=[  
} tQWWgLM  
oL]mjo=jN  
Yu'a<5f  
//停止文件下载 z v>Oh#  
public void siteStop() >OV<_(S4  
{ ~W<CE_/]k  
bStop = true; +b^]Pz5  
for(int i=0;i<nStartPos.length;i++) NUCiY\td  
fileSplitterFetch.splitterStop(); hk%k(^ekU]  
Hou*lCA  
YutQ]zYA.  
} F|>05>8  
} (Yv{{mIy  
//负责部分文件的抓取 B MM--y@  
**FileSplitterFetch.java .}q]`<]ze  
*/ ;f:gX`"\  
package NetFox; ^i+[m  
}Z\wH*s`  
K UKACUL  
import java.io.*; >!L&>OOx  
import java.net.*; [E7MsX  
H3 , ut  
8-m 3e  
public class FileSplitterFetch extends Thread { `\bT'~P  
~2@Lx3t$  
W^es;5  
String sURL; //File URL VPt9QL(  
long nStartPos; //File Snippet Start Position `5q ;ssu  
long nEndPos; //File Snippet End Position yEq#Dr  
int nThreadID; //Thread's ID 5Fm av5  
boolean bDownOver = false; //Downing is over 8TE>IPjm  
boolean bStop = false; //Stop identical v?%LQKO  
FileAccessI fileAccessI = null; //File Access interface ]IZ>2!6r  
?s?$d&h  
`9Yn0B.  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (luKn&826  
{ 54{q.I@n  
this.sURL = sURL; +`B'r '  
this.nStartPos = nStart; $IVwA  
this.nEndPos = nEnd; "X04mQn15  
nThreadID = id; 8Hi!kc;f6>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 * RWm47  
} /)EY2Y'  
KB!5u9  
[ %}u=}@  
public void run() :]PM_V|  
{ P`S@n/}  
while(nStartPos < nEndPos && !bStop) +f>cxA  
{ ]5' d&f  
-Fxmsi  
=bLY /  
try{ ; Y"N6%  
URL url = new URL(sURL); N>|XS ,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =wG+Ao  
httpConnection.setRequestProperty("User-Agent","NetFox"); <P_ea/5:|  
String sProperty = "bytes="+nStartPos+"-"; ~=En +J}*  
httpConnection.setRequestProperty("RANGE",sProperty); S|em[D[Y^  
Utility.log(sProperty); /*$hx@ih  
fuUm}N7  
ujr(K=E  
InputStream input = httpConnection.getInputStream(); Y ya`&V  
//logResponseHead(httpConnection); y<- _(^  
JBC$Ku  
=WG=C1Z  
byte[] b = new byte[1024]; xyA-P& N  
int nRead; /6K Il  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) krB'9r<wa`  
{ x[(?#  
nStartPos += fileAccessI.write(b,0,nRead); ,+`HQdq  
//if(nThreadID == 1) `y^sITr  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -F\qnsZ2  
} ;apzAF  
2-'Opu  
$s\UL}Gc  
Utility.log("Thread " + nThreadID + " is over!"); ;@3FF  
bDownOver = true; F S"eM"z  
//nPos = fileAccessI.write (b,0,nRead); a.@qGsIH  
} ~Rpm-^  
catch(Exception e){e.printStackTrace ();} ~+G#n"Pn  
} P[ r];e  
} ?wb+L  
X^@ I].  
17|np2~  
//打印回应的头信息 vUA0FoOp  
public void logResponseHead(HttpURLConnection con) Sv'y e  
{ l"(6]Z 4  
for(int i=1;;i++) e`K)_>^n#  
{ Zg~nlO2  
String header=con.getHeaderFieldKey(i); EH*o"N`!r  
if(header!=null) Ju2l?Rr X  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a4 MZ;5  
Utility.log(header+" : "+con.getHeaderField(header)); 0aI;\D*Ts  
else |X19fgk  
break; k]A8% z  
} 7.Kc:7  
} bFS>)  
Bux [6O %  
Hr<o!e{Y  
public void splitterStop() px;/8c-  
{ U]|agz>  
bStop = true; E.`U`L  
} qZv =  
laKuOx}  
Pmg)v!"  
} iRV~Il#~!  
LQYy;<K  
8eBOr9l+j  
/* H)w(q^i  
**FileAccess.java S~Z|PLtF  
*//文件访问(定位,写) oR1^/e  
package NetFox; 5yZTcS z  
import java.io.*; -]uUYe c  
I<td1Y1q  
%+>s#Q2d  
public class FileAccessI implements Serializable{ %xZG*2vc!B  
}@1q@xU  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I){\0vb@  
RandomAccessFile oSavedFile; A - YBQPE  
long nPos; *^\HU=&  
X~=xXN.  
ltB .Q  
public FileAccessI() throws IOException $?G"GQ!.  
{ g>rp@M  
this("",0); l%ayI  
} $rF=_D6  
eN? Y7  
TL$EV>Nr  
public FileAccessI(String sName,long nPos) throws IOException D4Al3fe  
{ `;|5  
oSavedFile = new RandomAccessFile(sName,"rw"); ^9OUzTF  
this.nPos = nPos; >_dx_<75&  
oSavedFile.seek(nPos); .nu @ o40  
} T<3BT  
fKC3-zm  
=<r8fXWZ  
public synchronized int write(byte[] b,int nStart,int nLen) g]c[O*NTL  
{ |Xi%   
int n = -1; U[L9*=P;  
try{  VGHWNMT  
oSavedFile.write(b,nStart,nLen); s>k Uh  
n = nLen; 7|\@zQ h   
} `\`>0hlu  
catch(IOException e) *L6PLe  
{ PWRy7d  
e.printStackTrace (); GZS1zTwBL  
} @vL20O.  
j*"3t^|-  
&8&d3EQ  
return n; .:p2Tbo  
} /+*#pDx/zW  
R[z`:1lo  
a,F&`Wg  
} 8.' #?]a  
KrVcwAcq|1  
`RU[8@ 2%  
/* T_b^ Tc`  
**SiteInfoBean.java WwH+E]^e+  
*/ SG}V[Glk  
package NetFox; JO=[YoTr  
|(m oWY=  
IK,|5]*Ar  
public class SiteInfoBean { D|Iur W1f  
%75xr9yOP  
}i {sg#  
private String sSiteURL; //Site's URL dzK{ Z  
private String sFilePath; //Saved File's Path `l2O?U-@  
private String sFileName; //Saved File's Name ? J} r  
private int nSplitter; //Count of Splited Downloading File !USd9  
8}H1_y-g[  
~\x:<)  
public SiteInfoBean() &l$Q^g  
{//nSplitter的缺省值为5 %ms'n  
//default value of nSplitter is 5 PB%-9C0  
this("","","",5); \s3]_1F;t  
} h)~=Dm  
f\'{3I29  
!O\;Nua  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N#lDW~e'  
{ 'r(1Nj  
sSiteURL= sURL; -a*K$rnB  
sFilePath = sPath; [I4ege>  
sFileName = sName; Kvsh  
this.nSplitter = nSpiltter; hcVJBK  
eh1Q7 ~  
o6f_l^+H  
} nJPyM/p  
{t};-q!v$j  
qE'9QQ>:b  
public String getSSiteURL() GgaTn!mJt  
{ Dnc(l(  
return sSiteURL; 1n%?@+W  
} .B#l5pfvP  
3@5=+z~CW  
%m:m}ziLQ  
public void setSSiteURL(String value) zlR?,h-[3  
{ I^o!n5VM  
sSiteURL = value; |ZodlYF  
} n wI!O  
ih?^t(i  
*'Z B*>  
public String getSFilePath() >~`C-K#  
{ s@MYc@k  
return sFilePath; ==i[w|  
} XqM3<~$  
cYXM__  
/1?R?N2>0  
public void setSFilePath(String value) @ HZKc\1  
{ cRX~z  
sFilePath = value; lL]y~u  
} 4&/j|9=X  
]|<w\\^A  
Xl@cHO=i  
public String getSFileName() 6<K6Y5<6  
{ 4v[~r1!V  
return sFileName; g$. \  
} @( n^T  
Ltjbxw"Qd  
`jS T  
public void setSFileName(String value) ?\8?%Qk  
{ j~j\\Y  
sFileName = value; hHqh{:q{v  
} Kx_h1{  
]Qm]I1P  
@ 49nJi  
public int getNSplitter() VLBE'3Qg 1  
{ 5k|9gICyd*  
return nSplitter; i-yy/y-N  
} @ P|LLG'  
OFje+S  
1Bxmm#  
public void setNSplitter(int nCount) r! Ay :r  
{ ~ ihI_q"  
nSplitter = nCount; ,vW:}&U  
} pLv$\ MiZ  
} ;-UmY}MU  
9n}p;3{f  
!|c|o*t{  
/* +2 Af&~T  
**Utility.java _)]CzBRq\6  
*/ !x'/9^i~v  
package NetFox; Z,iHy3`  
u1xSp<59C  
A)ipFB 6K  
public class Utility { u.rY#cS,-R  
wf1lyS  
|p$spQ  
public Utility() ePIiF_X  
{ _=|vgc  
y\{%\$  
ax 41N25  
} M:5b4$Qh<  
.jMq  
//线程睡眠 A<;SnXm  
public static void sleep(int nSecond) %kgkXc~6|x  
{ J*9$;  
try{ bTQNb!&  
Thread.sleep(nSecond); Ytgj|@jsp  
} aZbw]0q@o  
catch(Exception e) l3 DYg  
{ +MmHu6"1  
e.printStackTrace (); i1 RiGS  
} 3P;>XGCxZ  
} dK>7fy;mv  
trE{FT  
//日志 ZcYh) HD  
public static void log(String sMsg) =/\:>+p^.y  
{ QNDHOo>v  
System.err.println(sMsg); Hr$QLtr  
} "Ky; a?Y  
h,"4SSL  
^eoLAL  
public static void log(int sMsg) s=[h?kB  
{ ,!U=|c"k)  
System.err.println(sMsg); LY+|[qka  
} |*`Z*6n  
} 0?>dCu\  
c&L"N!4z  
d:yqj:  
/* ~Ch+5A;  
**TestMethod.java *}8t{ F@k  
*/ W0}B'VS.I  
package NetFox; p uT'y  
UT="2*3gz  
S]E.KLR?[;  
public class TestMethod { I" KN"v^  
+>4;Zd!@d  
} CfqG?)  
public TestMethod() IIyI=Wl pG  
{ ///xx/weblogic60b2_win.exe &?h,7 D;A  
try{ V%Sy"IG  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u_rdmyq$x/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _SA5e3#  
SiteFileFetch fileFetch = new SiteFileFetch(bean); cp o-.  
fileFetch.start(); U)3DQ6T99  
} fNrgdfo  
catch(Exception e){e.printStackTrace ();} R i^[i}  
tr7<]Hm:  
i E CrI3s  
} ~/*MY  
g(4xC7xK6  
1T[et-  
public static void main(String[] args) &d|r~NhP  
{ H@l}WihW  
new TestMethod(); !fj(tPq  
} ZI=v.wa  
} <ZB1Vi9}8  
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