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
  • 8286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
/* )`)cB)s  
**SiteFileFetch.java AQ&;y&+QR  
*/ _> *"6  
package NetFox; KLk37IY2\  
import java.io.*; eNNK;xXe#  
import java.net.*; z K&`&("4C  
Je/R'QP^8  
1DX=\BWp  
public class SiteFileFetch extends Thread { TS;MGi0`}  
>\e11OU0Gy  
nm)F tX|A  
SiteInfoBean siteInfoBean = null; //文件信息Bean <K43f#%  
long[] nStartPos; //开始位置 Bn.8wMB  
long[] nEndPos; //结束位置 /1Eg6hf9B  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 #>0nNR[$Y  
long nFileLength; //文件长度 }\@*A1*X2  
boolean bFirst = true; //是否第一次取文件 ~Oq(JM $M  
boolean bStop = false; //停止标志 )9*WmFc+#  
File tmpFile; //文件下载的临时信息 *]LM2J  
DataOutputStream output; //输出到文件的输出流 5b&'gd^d  
30<^0J.1  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) bV"0}|A~K  
public SiteFileFetch(SiteInfoBean bean) throws IOException YRK4l\_`  
{ =hA/;  
siteInfoBean = bean; /q=<OEC  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); A 9u9d\  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); .e6:/x~p*  
if(tmpFile.exists ()) O_E[F E:+  
{ P6MT[  
bFirst = false; *+ b[v7  
read_nPos(); Zffzyh  
} yEH30zSt  
else @A:Xct  
{ /h_BF\VBs  
nStartPos = new long[bean.getNSplitter()]; n@*NQ`(_  
nEndPos = new long[bean.getNSplitter()]; [P^ .=F  
} WPPmh~:  
6s6[sUf=l&  
qLR)>$  
Agl[Z>Q  
} zEu*q7  
=KX:&GU  
NK#f Gz*,(  
public void run() k?_Miqr  
{ qp7>_B  
//获得文件长度 NJ|8##Z>  
//分割文件 @Fo0uy\ G  
//实例FileSplitterFetch XRZmg "  
//启动FileSplitterFetch线程 RJ0w3T]7  
//等待子线程返回 #q%&,;4  
try{ c(o8uWn  
if(bFirst) oM< 9]jK}  
{ GSypdEBj+w  
nFileLength = getFileSize(); $Q62 7  
if(nFileLength == -1) Mq$e5&/  
{ 2 Y%$6NX  
System.err.println("File Length is not known!"); nH;^$b'LZ  
} `S%p D.g,2  
else if(nFileLength == -2) s{gdTG6v`  
{ 8NpQ"0X  
System.err.println("File is not access!"); :=-h'<D  
} *C$ W^u5h  
else 5)0R:  
{ >I+O@  
for(int i=0;i<nStartPos.length;i++) 4/$]wK`  
{ 3^8%/5$v  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); PQ1\b-I  
} .Zo8KwkFY  
for(int i=0;i<nEndPos.length-1;i++) D{ c`H}/`  
{ ibEQ52  
nEndPos = nStartPos[i+1]; q")}vN  
} ^"l4   
nEndPos[nEndPos.length-1] = nFileLength;  I"r*p?  
} H Jwj,SL  
} |ONkRxr@!  
hMdsR,Iq  
OD{Rh(Id  
//启动子线程 ]  OR ]  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A07FjT5w8  
for(int i=0;i<nStartPos.length;i++) 9"&HxyOfX  
{ )abo5   
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f.Jz]WXw,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wF}/7b54  
nStartPos,nEndPos,i); y;uk|#qnPS  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w_6h $"^x  
fileSplitterFetch.start(); !YCYmxw#  
} L[D}pL=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !x[ +rf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^ *RmT  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q_JES4ofx  
nEndPos = " + nFileLength); evq *&.6\  
// fileSplitterFetch[nPos.length-1].start(); j`(o\Fd )  
N n+leM  
>!?u8^C  
//等待子线程结束 +tl&Jjdm  
//int count = 0; PbCXcs  
//是否结束while循环 T~_+\w  
boolean breakWhile = false; )0YMi!&j`  
cSQvP.  
'xhX\?mD  
while(!bStop) 4k}u`8 a  
{ *SL v$A  
write_nPos(); VcA87*pel  
Utility.sleep(500); Q@nxGm  
breakWhile = true; 1jO/"d.8n  
Za5*HCo  
Gw$U0HA[,  
for(int i=0;i<nStartPos.length;i++) 5) nm6sf  
{ 1: XT r  
if(!fileSplitterFetch.bDownOver) $yBU ,lu}  
{ .(ki(8Z N  
breakWhile = false; S+7>Y? B!  
break; (Jy7  
} /(5 SJ(a  
} 7C F-?M!  
if(breakWhile) ?FxxH*>"  
break; ["kk.*&  
uv eTx  
*q\Ve)E}  
//count++; FlttqQQdf  
//if(count>4) /V^Gn;  
// siteStop(); b~z1%?  
} ,aU_bve  
<%B sb}h,  
9Y3_.qa(.  
System.err.println("文件下载结束!"); c\065#f!  
} ^/U-(4O05*  
catch(Exception e){e.printStackTrace ();} UzWf_r  
} r1}YN<+,s  
 W^Wr  
=bi:<%"  
//获得文件长度 TkM8GK-3  
public long getFileSize() q]DV49UK  
{ :D""c*  
int nFileLength = -1; i]JD::P_H  
try{ c=0S]_  
URL url = new URL(siteInfoBean.getSSiteURL());  mR)Xq=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VE`5bD+%e  
httpConnection.setRequestProperty("User-Agent","NetFox"); nn5tOV}QE  
eF823cH2x_  
F2saGpGH  
int responseCode=httpConnection.getResponseCode(); R%=u<O  
if(responseCode>=400) >,yE;zuw  
{ tt $DWmm  
processErrorCode(responseCode); V>>"nf,YO  
return -2; //-2 represent access is error ,6uON@  
} |#^wYZO1U  
T@ (MSgp9  
@FKm_q  
String sHeader; Z%E;*R2+:>  
4V@raI-  
n6Je5fE  
for(int i=1;;i++) i 3?=up!  
{ d kVF  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dDK4I3a  
//Utility.log(in.readLine()); W2?6f:  
sHeader=httpConnection.getHeaderFieldKey(i); /zJDQ'k0  
if(sHeader!=null) US[{ Q  
{ l 8qCg/ew  
if(sHeader.equals("Content-Length")) O~?H\2S  
{ .76T<j_  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QpxRYv  
break; % put=I  
} >slD.rb]  
} P MV;A{T  
else Xn@\p5<  
break; hLK5s1#K  
} "%ou'\}  
} @-qS[bV  
catch(IOException e){e.printStackTrace ();} O9?t,1  
catch(Exception e){e.printStackTrace ();} A/ZZ[B-  
`K5Lp>=R  
+GqK$B(x7  
Utility.log(nFileLength); 'Z5l'Ac  
b&BkT%aA(G  
?y_W%og W  
return nFileLength; \]uD"Jqv#  
} #}Y$+FtO  
&\),V1"  
BPs|qb-  
//保存下载信息(文件指针位置) zW.I7Z0^  
private void write_nPos() N1/)F k-z  
{ Gmi ^2?Z(  
try{ #[Z ToE4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Zq1Z rwPF  
output.writeInt(nStartPos.length); B?n 6o|8  
for(int i=0;i<nStartPos.length;i++) O =m_P}K  
{ v% a)nv  
// output.writeLong(nPos); @D1}).  
output.writeLong(fileSplitterFetch.nStartPos); pn"TFapJA  
output.writeLong(fileSplitterFetch.nEndPos); Sp/t[\,'  
} %EV\nwn6  
output.close(); \vwsRT 1  
} eYNu78u   
catch(IOException e){e.printStackTrace ();} 6bPoC$<Z  
catch(Exception e){e.printStackTrace ();} w1U2cbCr/  
} ~C M%WvS  
w(Jf;[o  
bvn%E H  
//读取保存的下载信息(文件指针位置) X?'ShXI  
private void read_nPos()  rG[iEY  
{ }\ kLh(  
try{ LL% Aw)Q`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1'Sr0 oEd3  
int nCount = input.readInt(); 5\!t!FL_  
nStartPos = new long[nCount]; n1!hfu7@s  
nEndPos = new long[nCount]; NSs"I]  
for(int i=0;i<nStartPos.length;i++) v\lhbpk  
{ Hreu3N  
nStartPos = input.readLong(); Yx#?lA2gx  
nEndPos = input.readLong(); R%Xhdcn7  
} ={~?O&Jh  
input.close(); X;:qnnO  
} :)JIKP%$\)  
catch(IOException e){e.printStackTrace ();} 2:[ -  
catch(Exception e){e.printStackTrace ();} J:D{5sE<|  
} [7Fx#o=da  
Y6W#u iqk  
U)v){g3w)  
private void processErrorCode(int nErrorCode) ?`T0zpC  
{ +|0f7RB+R  
System.err.println("Error Code : " + nErrorCode); IkWV|E  
} oyw*Z_9~  
X%X`o%AqC  
=:fN  
//停止文件下载 U~3uu &/r  
public void siteStop()  >;qAj!'  
{ Q' b@5o  
bStop = true; }^Ymg7wA  
for(int i=0;i<nStartPos.length;i++) /FJ.W<hw  
fileSplitterFetch.splitterStop(); qe/dWJBa  
LOO<)XFJ  
E^s<5BC;  
} o,NTI h  
} ccR#<Pb6q  
//负责部分文件的抓取 kz!CxI (  
**FileSplitterFetch.java 9Gh:s6  
*/ L/Tsq=  
package NetFox; 3bsuE^,.@  
b;;mhu  
6Dl]d %.  
import java.io.*;  C\`*_t  
import java.net.*; |(eRv?Qy@  
U3 t$h  
]S0tK  
public class FileSplitterFetch extends Thread { ob. Br:x  
&0`[R*S  
W^e"()d/Z  
String sURL; //File URL PP*',D3  
long nStartPos; //File Snippet Start Position 0%(.$c>:f  
long nEndPos; //File Snippet End Position Qr.SPNUFK  
int nThreadID; //Thread's ID  Uf,fd  
boolean bDownOver = false; //Downing is over OK] _.v}  
boolean bStop = false; //Stop identical rbt/b0ET  
FileAccessI fileAccessI = null; //File Access interface DYf3>xh>xb  
6lAHB*`  
'G)UIjl  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F[@M?  
{ 90Sp(  
this.sURL = sURL; 0FAe5 BE7  
this.nStartPos = nStart; < C1Jim  
this.nEndPos = nEnd; [,a2A  
nThreadID = id; dy' J~Eo7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1 !8 b9  
} X~2L  
t,]E5,1  
xg.o7-^M  
public void run() .P:mY C  
{ w<|Qezi3 w  
while(nStartPos < nEndPos && !bStop) Z1dLC'/b]  
{ Spm0DqqR?  
}!_ofe  
7Zw.mM!i  
try{ 2kfX_RK  
URL url = new URL(sURL); bXNM.K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #S|DoeFs  
httpConnection.setRequestProperty("User-Agent","NetFox");  o%SD\zk  
String sProperty = "bytes="+nStartPos+"-"; X,mqQ7+  
httpConnection.setRequestProperty("RANGE",sProperty); 4:0y\M5u  
Utility.log(sProperty); Vh}F#~BrI  
SJ8CBxA  
B:]%Iu|  
InputStream input = httpConnection.getInputStream(); PZ.q  
//logResponseHead(httpConnection); &:?2IAe  
A(@VjXl  
`#3FvP@&  
byte[] b = new byte[1024]; ozOvpi:k3%  
int nRead; O<>cuW(l  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @%b&(x^UD  
{ (:r80:  
nStartPos += fileAccessI.write(b,0,nRead); kSUpEV+/  
//if(nThreadID == 1) !(i}FFn{:  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NpAZuISD!  
} _I/uW|>  
[XbNZ6  
2tqj]i  
Utility.log("Thread " + nThreadID + " is over!"); CzfGb4  
bDownOver = true; |r<#>~*  
//nPos = fileAccessI.write (b,0,nRead); %1Nank!Zj  
} 7 (kC|q\4M  
catch(Exception e){e.printStackTrace ();} _O;2.M%@  
} hd N[wC]  
} 231,v,X[  
vp4NH]fJ  
^~DDl$NH  
//打印回应的头信息 #`o]{UfW  
public void logResponseHead(HttpURLConnection con) I3hN7  
{ = P@j*ix  
for(int i=1;;i++) |y$8!*S~(  
{ | k?r1dj%O  
String header=con.getHeaderFieldKey(i); i$gH{wn\`  
if(header!=null) ]t)#,'$^[W  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `|`Qrv 4}  
Utility.log(header+" : "+con.getHeaderField(header)); ,a'Y^[4k?  
else J^gElp  
break; v[XTH 2  
} |PxTm  
} fq<JX5DER  
s ;2ih)[  
U+ANSW/  
public void splitterStop() .^!<cFkCE  
{ TsF>Y""*M  
bStop = true; UfSqiu  
} TjY-C m  
fP8iz `n  
rv<_'yj  
} T=,A pa  
^-2|T__  
M]7>Ar'zsG  
/* %U?1Gf e  
**FileAccess.java G7N Rpr  
*//文件访问(定位,写) q+{$"s9v  
package NetFox; .C\##   
import java.io.*; cH48)  
b]6@ O8  
g:eq B&&  
public class FileAccessI implements Serializable{ jz$ ]"\G#  
;!(GwgllD  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9/#?]LJ  
RandomAccessFile oSavedFile; Xy]Pmt  
long nPos; yvIzgwN%s!  
P$#{a2  
]114\JE  
public FileAccessI() throws IOException !g7lJ\B  
{ 1LVO0lT  
this("",0); zff<#yK1  
} QWI)Y:<K/  
s"JD,gm$  
0Zh]n;S3m  
public FileAccessI(String sName,long nPos) throws IOException \e9rXh%  
{ d#1yVdqRl  
oSavedFile = new RandomAccessFile(sName,"rw"); SIZZFihcYh  
this.nPos = nPos; Fk#$@^c@  
oSavedFile.seek(nPos); 4 Kh0evZ  
} >/.w80<'  
#?C.%kD  
2y5d  
public synchronized int write(byte[] b,int nStart,int nLen) mX5%6{],  
{ ;~-M$a }4  
int n = -1; B+2E IaI  
try{ @hwe  
oSavedFile.write(b,nStart,nLen); )skz_a}]8  
n = nLen; BcxALRWE  
} "cz'|z`  
catch(IOException e) n?:%>Os$  
{ * zt?y  
e.printStackTrace (); Q N]y.(S)y  
} A/!"+Yfw  
ps_q3Cyp  
W<u,S  
return n; CB^.N>'  
} 2 9#jKh  
N?2C*|%f  
u'; 9zk/$  
} 26ae|2?  
722:2 {  
j;BlpRD}  
/* \l1==,wk  
**SiteInfoBean.java 1ne3CA=  
*/ 0k G\9  
package NetFox; yT-qT_.  
a4&Aw7"X  
CUnBi?Mi  
public class SiteInfoBean { b\S~uFq6  
|B {*so]  
*RM 3 _  
private String sSiteURL; //Site's URL L6./5`bs  
private String sFilePath; //Saved File's Path h + <Jv   
private String sFileName; //Saved File's Name s#H_ QOE  
private int nSplitter; //Count of Splited Downloading File N6HeZB" :  
qLV3Y?S!L  
VWK%6Ye0  
public SiteInfoBean() $wC'qV *  
{//nSplitter的缺省值为5 FfNUFx2N  
//default value of nSplitter is 5 &%`WXe-`R  
this("","","",5); X ?U'GLm  
} yA#nnu1  
8n35lI ( [  
C6'K)P[p  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e'MW"uCP}  
{ o Vpq*"  
sSiteURL= sURL; qTSe_Re  
sFilePath = sPath; m/3,;P.6  
sFileName = sName; 66-tNy  
this.nSplitter = nSpiltter; `|2g &Vn  
14DhJUV"b  
c~+KrWbZ~  
} )=VAEQhL-  
L'w]O -86  
2ZEDyQM  
public String getSSiteURL() bXSAZW f  
{ @'<=E AXe  
return sSiteURL; qrf90F)  
} szCB}WY  
dNf:I,<DCf  
)|/%]@` N  
public void setSSiteURL(String value) g`C\pdX"B  
{ V8#NXU g<!  
sSiteURL = value; [HI$[ :[  
} U!(es0rX  
_2Mpzv  
U C_$5~8p  
public String getSFilePath() GvZ[3GT  
{ pxn@rN#*  
return sFilePath; !;;7:!)P  
} < 0YoZSNGj  
f] _'icP  
0xY</S  
public void setSFilePath(String value) fejC ,H4I  
{ 9Dbbk/j|  
sFilePath = value; }3_ >  
} 7"F29\  
a7685Y  
CeeAw_*@  
public String getSFileName() mV^~  
{ b:cy(6G(  
return sFileName; BOWOH  
} %/ctt_p0x  
*`8JJs0g  
loC~wm%Ql  
public void setSFileName(String value) D^gS.X^  
{ [X91nUz#  
sFileName = value; wh)F&@6 R!  
} Y::O*I2  
je5[.VTM  
:a^/&LbLm  
public int getNSplitter() q}!h(-y}5n  
{ 80ox$U  
return nSplitter; ,Ha<lU2K  
} SF`(`h0e  
|s;']  
l))Q/8H  
public void setNSplitter(int nCount) \VA*3U^@  
{ D*j^f7ab  
nSplitter = nCount; #IJe q0TVB  
} S@g(kIo]  
} t cO{CI  
~Hu!iZ2]  
]T'7+5w  
/* T2 S fBs  
**Utility.java VFzIBgJ3  
*/ p!5'#\^f  
package NetFox; [(gXjt-  
;s;3cC!  
xW]65iav  
public class Utility { bAbR0)  
#f< v%  
u`&lTJgF/O  
public Utility() #y[U2s Se  
{ YM};85K  
T@Y, 7ccpd  
yYaoA/0  
} ""Da 2Md  
;1s+1G}_z  
//线程睡眠 z:@:B:E  
public static void sleep(int nSecond) {}$Zff   
{ Zazff@O *  
try{ P#,;)HF  
Thread.sleep(nSecond); *yaS^k\  
} 0y6M;"&~E  
catch(Exception e) &!OEd ]  
{ *ziR&Fr!  
e.printStackTrace (); yIrJaS-  
} Zk`yd8C  
} 'E+"N'M|  
o<G#%9j  
//日志 "VZXi_P  
public static void log(String sMsg) u*TC8!n  
{ N+h05`  
System.err.println(sMsg); l?=\9y  
} D}q"^"#T  
"4;nnq  
_'LZf=V0  
public static void log(int sMsg) -(t7>s  
{ pF4Z4?W  
System.err.println(sMsg); ;8eKAh  
} __2<v?\  
} P RWb6  
Qr9;CVW  
y TD4![  
/* fT|A^  
**TestMethod.java  UXs)$  
*/ xC,x_:R`  
package NetFox; bh<;px-  
Vv45w#w;  
KWZhCS?[(  
public class TestMethod { 3iIy_nWC  
REU,"  
3f] ;y<Km  
public TestMethod() pK@=]K~l0  
{ ///xx/weblogic60b2_win.exe USEb} M`  
try{ j/z=<jA  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?%h$deJ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 68Gywk3]=u  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _ i}W1i  
fileFetch.start(); l2qvYNMw  
} N,c!1: b  
catch(Exception e){e.printStackTrace ();} Aj)Q#Fd[  
xwf-kwF8^  
nUOi~cs  
} L%T(H<G  
.VCY|KZ  
pA6KiY&  
public static void main(String[] args) EUi 70h +  
{ V}Y*Yv  
new TestMethod(); E4L?4>V@\  
} ]7O<|8n!d  
} W&IG,7tr  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八