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
  • 8951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
/* *^+8_%;1  
**SiteFileFetch.java z)N8#Y~vn  
*/ }cuU5WQ?%  
package NetFox; `) s]T.-  
import java.io.*; fH[Yc>(oj  
import java.net.*; ^y"5pf SR  
ikd~k>F  
Oo<L~7B  
public class SiteFileFetch extends Thread { 7kJ =C  
D0NSzCHx  
HC4qP9Gs  
SiteInfoBean siteInfoBean = null; //文件信息Bean CqGi 2<2  
long[] nStartPos; //开始位置 &' E(  
long[] nEndPos; //结束位置 |E)-9JSRy  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 *mH++3h  
long nFileLength; //文件长度 P5/\*~}  
boolean bFirst = true; //是否第一次取文件 Fy_D[g  
boolean bStop = false; //停止标志 kpFt  
File tmpFile; //文件下载的临时信息 e7rD,`NiV  
DataOutputStream output; //输出到文件的输出流 ";\na!MT  
5{ ?J5  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) z.EpRJn  
public SiteFileFetch(SiteInfoBean bean) throws IOException ZdQt!  
{ ,kiyx h^  
siteInfoBean = bean; YmXh_bk  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 'o41)p  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); `rEu8u  
if(tmpFile.exists ()) c!n\?lB  
{ CsfGjqpf  
bFirst = false; e%_2n=p~)%  
read_nPos(); RQ}0f5~t  
} ; C/:$l  
else q5<'pi   
{ z2:^Qg  
nStartPos = new long[bean.getNSplitter()]; +zM WIG  
nEndPos = new long[bean.getNSplitter()]; -'ff0l  
} G 92\` Q  
aYc*v5Q N3  
RJ+i~;-  
'a8{YT4  
} Fo  K!JX*  
-L=aZPW`M  
>9F&x>~  
public void run() S+aXlb  
{ ;jC}.] _)w  
//获得文件长度 4O}ZnE1[  
//分割文件 3^NHV g  
//实例FileSplitterFetch BC|=-^(  
//启动FileSplitterFetch线程 h+ixl#:  
//等待子线程返回 x93t.5E6  
try{ yb{ud  
if(bFirst) 1nHQ)od  
{ BllS3I}V  
nFileLength = getFileSize(); =z_.RE  
if(nFileLength == -1) iKs @oHW  
{ AXbDCDA  
System.err.println("File Length is not known!"); @K{1O|V  
} %#5yC|o9Pn  
else if(nFileLength == -2) tkQ#mipAj  
{ SvE3E$*  
System.err.println("File is not access!"); LHit9O[_/s  
} &d1|B`gL|  
else OUoN  
{ y;oPg4  
for(int i=0;i<nStartPos.length;i++) fGK=lT$  
{ >iE/t$%1  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); UEkn@^&bg  
} K ?R* )_  
for(int i=0;i<nEndPos.length-1;i++) !h\>[O  
{ 6k569c{7  
nEndPos = nStartPos[i+1]; ([vyY}43h  
} 9 GEMmo3  
nEndPos[nEndPos.length-1] = nFileLength; @D$^- S6  
} Tvdg:[V<  
} ."HDUo2D7  
hn-+]Y:  
^ud-N;]MKs  
//启动子线程 LmCr[9/  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =EE>QM  
for(int i=0;i<nStartPos.length;i++) R<* c   
{ k9]M=eO  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H] i.\2z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b A/,{R  
nStartPos,nEndPos,i); /=o~7y  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pn&!C*,  
fileSplitterFetch.start(); G)<NzZo  
} x?5D>M/Y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {Y0Uln5u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1#]0\Y(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4gyC?#Ede  
nEndPos = " + nFileLength); _SVIY@K|/  
// fileSplitterFetch[nPos.length-1].start(); O $ p  
\W%Aeg*c  
cOhx  
//等待子线程结束 ,q[aV 6kO  
//int count = 0; \&tv *  
//是否结束while循环 d'bAM{R>  
boolean breakWhile = false; 0O@UT1 M;v  
idG}p+(;  
h mijp1u  
while(!bStop) cD&QN9  
{ B4uJT~,7>  
write_nPos(); NFYo@kX> G  
Utility.sleep(500); Ev%_8CO4e  
breakWhile = true; k4@$vxy0  
H YA<  
_BC%98:WP  
for(int i=0;i<nStartPos.length;i++) ,}8|[)"  
{ )\xDo<@  
if(!fileSplitterFetch.bDownOver) Hj\iI p  
{  gAFu  
breakWhile = false; [.ya&E)x  
break; \my5E\  
} moop.}O<  
} jUtFDw  
if(breakWhile) VXfp=JE  
break; sN"JVJXi  
Ah_,5Z@&R  
9i^dQV.U=  
//count++; +1uAzm4SL  
//if(count>4) \E}YtN#  
// siteStop(); 2cnyq$4k  
} j'\!p):H  
[wLK*9@&  
S)n+E\c  
System.err.println("文件下载结束!"); d9qA\ [  
} a;GuFnfn,  
catch(Exception e){e.printStackTrace ();} s|cL mL[  
} k'(d$;Jgr  
By&ibN),  
v@qU<\Y>  
//获得文件长度 ;$il_xA)\>  
public long getFileSize() :" ta#g'  
{ 47/14rY 2  
int nFileLength = -1; ?QbxC,& i  
try{ 0Z11V9Jk  
URL url = new URL(siteInfoBean.getSSiteURL()); @N(*1,s2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NQ9/,M  
httpConnection.setRequestProperty("User-Agent","NetFox"); [9-&Lq_ g  
M15jwR!:M  
],?$&  
int responseCode=httpConnection.getResponseCode(); 3RbPc8($Y  
if(responseCode>=400) [?QU'[  
{ jV)4+D  
processErrorCode(responseCode); REK(^1 h  
return -2; //-2 represent access is error 5LYzX+a)  
} Hv3<gyD  
;Z asK0  
y;$ !J  
String sHeader; @ ,9cpaL3  
)iU@P7W=  
m-wK8]t9  
for(int i=1;;i++) 9 SBVp 6'  
{ Rr%CP[bH  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [$x&J6jF.  
//Utility.log(in.readLine()); ^!FLi7X  
sHeader=httpConnection.getHeaderFieldKey(i); .XZq6iF9  
if(sHeader!=null) X5Fi , /H  
{ 5`3Wua  
if(sHeader.equals("Content-Length")) uOv0ut\\G  
{ :(?F(Q^  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  l,lfkm  
break; CRh.1-  
} ?as1^~  
} IEP^u `}  
else )%(V.?eW  
break; Q7{/ T0  
} 7_ G$&  
} mne?r3d  
catch(IOException e){e.printStackTrace ();} #X`qkW.T<  
catch(Exception e){e.printStackTrace ();} C1M @;  
.7`c(9<  
S^z t>  
Utility.log(nFileLength); BYKONZu  
XwlF[3VbiX  
qX%oLa  
return nFileLength; Y0 ?<~Gf  
} U;q GUqI  
]Jum(1Bo  
>"/Sa_w  
//保存下载信息(文件指针位置) DKG99biJN  
private void write_nPos() b" PRa|]  
{ 7`pK=E}+  
try{ OMz_xm.UPi  
output = new DataOutputStream(new FileOutputStream(tmpFile)); QI WfGVc-  
output.writeInt(nStartPos.length); EyK F5TP0  
for(int i=0;i<nStartPos.length;i++) U=vh_NHj  
{ G@=H=' :~  
// output.writeLong(nPos); NGs@z^&V  
output.writeLong(fileSplitterFetch.nStartPos); OH_mZA  
output.writeLong(fileSplitterFetch.nEndPos); 7lH.>n  
} u|Tg*B  
output.close(); ZR*Dl.GWY  
} j96\({;k  
catch(IOException e){e.printStackTrace ();} ,?KN;~t#vz  
catch(Exception e){e.printStackTrace ();} +>BD^[^^  
} 6qF9+r&e ?  
'<!T'l:R:/  
<?E~Qc t  
//读取保存的下载信息(文件指针位置) Oe_*(q&  
private void read_nPos() `%<^$Ng;  
{ ~6!TMVr  
try{ _Z0O]>KH  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #[ TOe  
int nCount = input.readInt(); ]7/6u.G7R  
nStartPos = new long[nCount]; 8w\ZY>d   
nEndPos = new long[nCount]; *f*o ,~8V1  
for(int i=0;i<nStartPos.length;i++) WW[Gne  
{ )d =8)9B  
nStartPos = input.readLong(); $8;`6o`  
nEndPos = input.readLong(); D"vl$BX  
} <ZXK}5SZ#  
input.close(); t \;,$i  
} {~0r3N4Zl  
catch(IOException e){e.printStackTrace ();} ":Uv u[-  
catch(Exception e){e.printStackTrace ();} .?NraydwV  
} D6NgdE7b  
F&6Xo]?  
bL 9XQ:$C  
private void processErrorCode(int nErrorCode) ,+U,(P5>s  
{ 2)4oe  
System.err.println("Error Code : " + nErrorCode); ELgq#z  
} ~^ ^|]s3  
CS\T@)@t  
^,sKj-  
//停止文件下载 T~G~M/  
public void siteStop() tEl_a~s*3?  
{ a`E1rK'  
bStop = true; &Z%|H>+;T  
for(int i=0;i<nStartPos.length;i++) tjWf`#tH>H  
fileSplitterFetch.splitterStop(); oRZ--1oR_  
4cQ|"sOzD  
upefjwm  
} Bf+7;4-  
} svj0;x5  
//负责部分文件的抓取 Ns#R`WG)  
**FileSplitterFetch.java UWIw/(Mv/]  
*/ sF!nSr  
package NetFox; 7]pi.1i  
7>$&CWI  
f~-Ipq;F  
import java.io.*; *L+)R*|:&  
import java.net.*; $PbwC6>8  
xwe^_7  
b.lK0 Xo  
public class FileSplitterFetch extends Thread { mZ! 1Vh  
#57D10j  
0hoi=W6AQ  
String sURL; //File URL o^*k   
long nStartPos; //File Snippet Start Position qrt2BT)  
long nEndPos; //File Snippet End Position $`'Xb  
int nThreadID; //Thread's ID R A^-Pa.O  
boolean bDownOver = false; //Downing is over rhQv,F9  
boolean bStop = false; //Stop identical HTw7l]]  
FileAccessI fileAccessI = null; //File Access interface {~a+dEz  
4O1[D? )`x  
%D $+Z(  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %[J|n~8_Z  
{ ?o883!&v  
this.sURL = sURL; vC|V8ea  
this.nStartPos = nStart; xa]e9u%  
this.nEndPos = nEnd; ['#3GJz-  
nThreadID = id; )a0%62  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;($"_h  
} /^^wHW:  
F?*ko,  
JR^#NefJ  
public void run() yf@DaIG  
{  Unc_e  
while(nStartPos < nEndPos && !bStop) )D>= \ Me  
{ *wNO3tP't  
5 4vDP9  
x-Ug(/!^  
try{ Kjfpq!NYE  
URL url = new URL(sURL); *fg|HH+i  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BE LxaV,  
httpConnection.setRequestProperty("User-Agent","NetFox"); SM1[)jZ-  
String sProperty = "bytes="+nStartPos+"-"; y~-dQ7r  
httpConnection.setRequestProperty("RANGE",sProperty); Yj#4{2A  
Utility.log(sProperty); |a{~Imz{  
SQ0t28N3h  
#dEMjD  
InputStream input = httpConnection.getInputStream(); &* 1iW(x  
//logResponseHead(httpConnection); oJ`cefcWo  
'pQ\BH  
8AQ@?\Rc"2  
byte[] b = new byte[1024]; vAH`tPi>  
int nRead; {(j1#9+9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =*Ru 2  
{ FdFN4{<QZ  
nStartPos += fileAccessI.write(b,0,nRead); |xX>AMZc)D  
//if(nThreadID == 1) Jh!'"7  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pon0!\ZT=  
} X J{b_h#N  
+#=l{_Z,ZJ  
$Q'S8TU  
Utility.log("Thread " + nThreadID + " is over!"); p|,3X*-ynx  
bDownOver = true; nQ}$jOU &  
//nPos = fileAccessI.write (b,0,nRead); rUOl+p_47  
}  *CS2ndp  
catch(Exception e){e.printStackTrace ();} Y}UVC|Ef  
} M,(UCyT  
} V<W$ h`  
nr>Os@\BU  
V3t;V-Lkt  
//打印回应的头信息 nLcOz3h  
public void logResponseHead(HttpURLConnection con) K%iA-h  
{ KVA~|j B  
for(int i=1;;i++) AttS?TZr  
{ O=2SDuBZ  
String header=con.getHeaderFieldKey(i); j8 |N;;MN  
if(header!=null) {IR-g,B  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E3P2  
Utility.log(header+" : "+con.getHeaderField(header)); g+  P  
else 8 O% ?t  
break; w4%yCp[,  
} y)]L>o~  
} 1Bhd-  
q[Ed6FM$~  
c3]X#Qa#m$  
public void splitterStop() 7ElU5I<S  
{ 2ms@CQy(00  
bStop = true; zc#$hIi  
} b<1+q{0r  
IyJHKDFk  
%UnL,V9)  
} )Z qY`by!  
gt Vnn]Jh  
&8R !`uh1  
/* :,[=g$CT:  
**FileAccess.java d]!`II  
*//文件访问(定位,写) 5?M d  
package NetFox; ^p}|""\j  
import java.io.*; SoPiEq  
N:nhS3N<L  
"2 "gTS  
public class FileAccessI implements Serializable{ ;(I')[R "  
,UE>@;]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m&!4*D  
RandomAccessFile oSavedFile; h qT6]*  
long nPos; ).D+/D/"2  
Rt=zqfJ  
Q-7C'|  
public FileAccessI() throws IOException LUN"p#1  
{ -Mx\W|YK  
this("",0); wu53e= /  
} YOE!+MiO  
4_&+]S  
k?7V#QW(  
public FileAccessI(String sName,long nPos) throws IOException o{r<=X ysM  
{ RW I7eC  
oSavedFile = new RandomAccessFile(sName,"rw"); #ssSs]zl  
this.nPos = nPos; jS<(O o  
oSavedFile.seek(nPos); %f'mW2  
} E=eK(t(8  
noL&>G  
pN?geF~t|  
public synchronized int write(byte[] b,int nStart,int nLen) }XcYIo#+t  
{ T_3JAH e  
int n = -1; XMpa87\  
try{ {a6cA=WTPd  
oSavedFile.write(b,nStart,nLen); '"Z\8;5i  
n = nLen; t'{IE!_  
} "`q:  
catch(IOException e) g+1&liV  
{ ~>-MVp  
e.printStackTrace (); p;0p!~F=49  
} Y5,[udF:O  
":!7R<t  
NcMohpkq  
return n; ^T&@(|o  
} AAW])c`.  
/|MHZ$Y9w?  
LfsqtQ=J`  
} mtd ,m  
pEp`Z,p  
7G]v(ay  
/* vnr{Ekg  
**SiteInfoBean.java 9Q /t+  
*/ x,81#=m^h  
package NetFox; ::`#qa4!  
$LkTu  
734f &2  
public class SiteInfoBean { 0s'h2={iI  
}"x#uG  
]:_s7v  
private String sSiteURL; //Site's URL k3yA*Ec  
private String sFilePath; //Saved File's Path $s.:H4:I  
private String sFileName; //Saved File's Name (<KFA,  
private int nSplitter; //Count of Splited Downloading File hteAuz4H  
4}xw&x  
2&o jQhe  
public SiteInfoBean() I6-.;)McO  
{//nSplitter的缺省值为5 v1O1-aM  
//default value of nSplitter is 5 >K;DBy*  
this("","","",5); =IH~:D\&  
} o|G[/o2  
XDQ5qfE|  
c$P68$FB  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) JEh(A=Eu>  
{ kVe4#LT  
sSiteURL= sURL; YM r2|VEU[  
sFilePath = sPath;  ,7h0y  
sFileName = sName; "zZ Z h  
this.nSplitter = nSpiltter; `~k`m{4.a  
6Q*Zy[=  
*YO^+]nmY  
} N5d)&a 7?  
gzd<D}2F~  
Kg6[  
public String getSSiteURL() e%_J O7  
{ OaeX:r+&Q  
return sSiteURL; vN9R. R  
} cMK}BHOC  
E^4}l2m_  
ORx6r=zg  
public void setSSiteURL(String value) c4V%>A  
{ iz%wozf  
sSiteURL = value; cXod43  
} \)`OEGdOR\  
ko{7^]gR  
U[EZ, 7n8  
public String getSFilePath() ^V7'S<  
{ c:I %jm  
return sFilePath; 1Eh6ti  
} Y?v{V>;*A  
G_]zymXQ  
U!i1~)s  
public void setSFilePath(String value) ]_(J8v  
{ uL{CUt  
sFilePath = value; /*2)|2w  
} IqAML|C  
|i\%> Y,  
+ l hJ8&  
public String getSFileName() lG5KZ[/Or  
{ '\M]$`Et  
return sFileName; 5=_bK^Am  
} Tx>V$+al  
fSF_O}kLp  
gY&WH9sp?9  
public void setSFileName(String value) s[bQO1g;*  
{ \IaUsx"#o{  
sFileName = value; ZM16 ~k  
} $1 t IC_  
WZM  
UR~s\m  
public int getNSplitter() $f?GD<}?7r  
{ v>0I=ut  
return nSplitter; p""\uG'  
} +"1fr  
.XT]\'vW  
-v! ;  
public void setNSplitter(int nCount) gA}?X  
{ zfw=U \  
nSplitter = nCount; qV0GpVJZU?  
} wxo*\WLe  
} G=/^]E  
#y-R*4G  
Du #>y!  
/* Cto>~pV  
**Utility.java c] -  
*/ +ib&6IU  
package NetFox; (q@%eor&}  
hg2Ywzfm-  
2]]}Xvx4#  
public class Utility { h~lps?.#b  
ot0g@q[3  
5PsjGvm.%  
public Utility() n^|SN9 _r  
{ l >~Rzw  
=o4gW`\z  
\%&):OD1  
} D"gv:RojD  
d uP0US  
//线程睡眠 8*;>:g  
public static void sleep(int nSecond) sJ{r+wY  
{ 8<Pi}RH  
try{ ~b @"ir+g4  
Thread.sleep(nSecond); Z((e-T#,  
} 5"y)<VLJX  
catch(Exception e) G.r .Z0  
{ gO{$p q}  
e.printStackTrace (); cJf&R^[T  
} )t((x  
} 85e*um^  
_6!iv  
//日志 lid0 YK-  
public static void log(String sMsg) !mmSF1f  
{ Tm$8\c4V:*  
System.err.println(sMsg); }@"v7X $  
} v"o_V|  
`=S%!akj  
x2TE[#><  
public static void log(int sMsg) |8tKN"QG  
{ Po&'#TC1  
System.err.println(sMsg); # [ +n(  
} #&ei  
} +IMt$}7[  
, `PYU[  
ht#,v5oG>f  
/* EeH ghq  
**TestMethod.java @Ko#nDEq  
*/ -/ G#ls|?  
package NetFox; 39MOqVc  
5g.w"0MkY  
qHgzgS7a  
public class TestMethod { U&43/;<,  
!L( )3=  
k{O bm g  
public TestMethod() kZhd^H.  
{ ///xx/weblogic60b2_win.exe IwBO#HR~)  
try{ D<:zw/IRE  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K:A:3~I!NW  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v}id/brl  
SiteFileFetch fileFetch = new SiteFileFetch(bean); *2fJdY  
fileFetch.start(); );h  
} XD" 4t4~>  
catch(Exception e){e.printStackTrace ();} @+1AYVz(k  
B`gH({U  
I2krxLPd  
} 0dQ\Y]b  
Z?d][zGw  
q&}+O  
public static void main(String[] args) i9V,  
{ c$lZ\r"  
new TestMethod(); mN> (n+ly  
} Q+/P>5O/  
} x0%yz+i{:  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八