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
  • 11348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
/* 2*n~r  
**SiteFileFetch.java 28}L.>5k  
*/ mv$gL  
package NetFox; {Ov{O,c 5  
import java.io.*; &f)pU>Di  
import java.net.*; G/(tgQ  
wI F'|"  
n7n-uc  
public class SiteFileFetch extends Thread { n{m[ j+UG  
Rp_}_hL0  
/;}o0 DYeW  
SiteInfoBean siteInfoBean = null; //文件信息Bean t""Y -M  
long[] nStartPos; //开始位置 Nh4&3"g|  
long[] nEndPos; //结束位置 CzDg?wb  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &RHx8zScP  
long nFileLength; //文件长度 K\lu;   
boolean bFirst = true; //是否第一次取文件 )U}`x }:,  
boolean bStop = false; //停止标志 bQ0+Y?,+/  
File tmpFile; //文件下载的临时信息 8KdcU [w]  
DataOutputStream output; //输出到文件的输出流 5GJa+St?  
dg(sRTi{  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ^p%3@)&  
public SiteFileFetch(SiteInfoBean bean) throws IOException BGu<1$ G  
{ z<. 6jx@  
siteInfoBean = bean; uSxldc  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); \x8'K  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Gch3|e  
if(tmpFile.exists ()) DsHm,dZ  
{ Te^_gdf  
bFirst = false; Je K0><  
read_nPos(); 8ux  
} o7v9xm+  
else ;_=dB[M  
{ zItGoJu  
nStartPos = new long[bean.getNSplitter()]; %wJ?+D/  
nEndPos = new long[bean.getNSplitter()]; nIUts?mB  
} ,v9*|>4  
TD!c+ ${w  
G/1V4-@  
yOk]RB<'r  
} vsB3n$2@u  
 @]V_%,  
`Q>qmf_Fi  
public void run() ExOSHKU,e  
{ Z?eedVV@  
//获得文件长度 0o 8V8 :  
//分割文件 6D*x5L-1o  
//实例FileSplitterFetch J b7^'P  
//启动FileSplitterFetch线程  y]ya.YG  
//等待子线程返回 *44E'Dxv  
try{ O%} hNTS"  
if(bFirst) ]9 9; 7  
{ S'IQbHz*  
nFileLength = getFileSize(); 5~i}!n  
if(nFileLength == -1) 3#`Sk`z<  
{ Te>m9Pav  
System.err.println("File Length is not known!"); sA,2gbW  
} PiNf;b^9  
else if(nFileLength == -2) =cx_3gCr{  
{ lO1]P&@  
System.err.println("File is not access!"); TSRl@QVy  
} RAxp2uif  
else CL!s #w1I\  
{ 0y;1D k!  
for(int i=0;i<nStartPos.length;i++) reNUIDt/c  
{ !F$o$iq  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 92/_!P>  
} G8b`>@rZ  
for(int i=0;i<nEndPos.length-1;i++) ?ViU%t8J5  
{ 'FG@Rg (  
nEndPos = nStartPos[i+1]; `] Zil8n  
} *!}bU`  
nEndPos[nEndPos.length-1] = nFileLength; Xh*Nu HH  
} ;x u&%n[6@  
} Uee$5a>(  
zhI"++  
0T:U(5Y9  
//启动子线程 5^{).fig  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; % hRH80W|  
for(int i=0;i<nStartPos.length;i++) `k9a$@Xg  
{ 0(^ N  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $ 3.Y2&$T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y0o{@)Y:  
nStartPos,nEndPos,i); eqU y>  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7<93n`byM  
fileSplitterFetch.start(); o-<.8Z}>at  
} :CXm@yF~4=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f(c#1AJE53  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mqQC`Aqx:  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @dhnpR :L  
nEndPos = " + nFileLength); 6J3<k(#:  
// fileSplitterFetch[nPos.length-1].start(); 'u:J "  
8+&Da  
D [K!xq  
//等待子线程结束 edfb7prfTl  
//int count = 0; jh~E!%d77  
//是否结束while循环 7hKfxw-X@  
boolean breakWhile = false; SJ&+"S&  
S@WT;Q2Z  
z3|5E#m  
while(!bStop) *7yrm&@nG  
{ SA,+oq(  
write_nPos(); *V@t]d$=#  
Utility.sleep(500); %$+bO/f  
breakWhile = true; O|&SL03Z8  
aydf# [F  
*#o2b-[V  
for(int i=0;i<nStartPos.length;i++) ])Z p|?Y  
{ W!b'nRkq  
if(!fileSplitterFetch.bDownOver) |k/;1.b!9(  
{ -^$IjK-N  
breakWhile = false; < _ <?p&  
break; \|R\pS}4  
} k6|/ik9C  
} 7,R ~2ss5z  
if(breakWhile) cg}lF9;d  
break; zw%1 a 3!  
Xcci)",!  
S 0mt8/ M  
//count++; a)M3t  
//if(count>4) ujeN|W  
// siteStop(); d{c06(#_  
} #9]O92t2UV  
< *db%{  
`s_k+ g  
System.err.println("文件下载结束!"); HurF4IsHk  
} nM H:7[x3  
catch(Exception e){e.printStackTrace ();} O?qM=W  
} 8AmB0W> e  
6JE_rAab  
xPP]RoPR  
//获得文件长度 tx}=c5  
public long getFileSize() xZ`h8  
{ -y8> c0u  
int nFileLength = -1; @8|i@S@4  
try{ 9&OhCrxW-  
URL url = new URL(siteInfoBean.getSSiteURL()); Y]+KsiOL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -;&-b>b  
httpConnection.setRequestProperty("User-Agent","NetFox"); _5v]69C#  
Jr,**,wA  
Qa,$_ ,E  
int responseCode=httpConnection.getResponseCode(); jFwJ1W;?-  
if(responseCode>=400) vk|xYDD  
{ ;% l0Ml>  
processErrorCode(responseCode); _?;74VWA  
return -2; //-2 represent access is error fI-f Gx  
} Eyg F,>.4  
v=?/c-J*  
7y=1\KW(  
String sHeader; CjmF2[|  
:2AlvjvjZ  
Qsr+f~"W  
for(int i=1;;i++) (bGk=q=M  
{ NnO%D^P]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u~1 ,88&U  
//Utility.log(in.readLine()); .N  Z  
sHeader=httpConnection.getHeaderFieldKey(i); GBGna3  
if(sHeader!=null) r5PZ=+F  
{ *~8g:;u  
if(sHeader.equals("Content-Length")) Kd7Lpw1u]  
{ \!Ap<  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BYb"[qPV  
break; J''lOj(@  
} \NQ[w7  
} kQO5sX$;  
else QzV%m0  
break; ZEG~ek=jM  
} hGU 3DKHT  
} .}iRe}=  
catch(IOException e){e.printStackTrace ();} <l$ vnq  
catch(Exception e){e.printStackTrace ();} co>IJzg  
(iY2d_FQ[  
rnM C[  
Utility.log(nFileLength); O5A]{ W  
Z#s-(wf  
rh6 e  
return nFileLength; X6n8Bi9Ik  
} L#`X;:   
,o [FUi(#@  
D1Q]Z63,  
//保存下载信息(文件指针位置) ]|B_3* A  
private void write_nPos() p}|<EL}Z9  
{ H.)J?3  
try{ G PL^!_  
output = new DataOutputStream(new FileOutputStream(tmpFile)); G( #EW+  
output.writeInt(nStartPos.length); !r9~K^EI  
for(int i=0;i<nStartPos.length;i++) 3tCT"UvTD  
{ y+$a}=cb0  
// output.writeLong(nPos); Ba9"IXKH  
output.writeLong(fileSplitterFetch.nStartPos); }C5Fvy6uz  
output.writeLong(fileSplitterFetch.nEndPos); /_tN&[  
} <(BIWm*  
output.close(); ])vqXjN6"  
} 8hZc#b;  
catch(IOException e){e.printStackTrace ();} 8FgF6ip  
catch(Exception e){e.printStackTrace ();} yUg'^SEbLk  
} )4jS}  
@Qd5a(5WM  
s"X0Jx}  
//读取保存的下载信息(文件指针位置) H=*2A!O[_  
private void read_nPos() {&pBy  
{ a0hgF_O1  
try{ Fhs/<w-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _`xhP-,`S  
int nCount = input.readInt(); s~g]`/h$r  
nStartPos = new long[nCount]; U DHMNubB  
nEndPos = new long[nCount]; #kAk d-QY6  
for(int i=0;i<nStartPos.length;i++) ?)e6:T(  
{ 'o1lJ?~kH  
nStartPos = input.readLong(); z"V`8D  
nEndPos = input.readLong(); >UV?n XP}  
} "cDc~~3/@  
input.close(); 2\G[U#~bi  
} r,wC5%&Za  
catch(IOException e){e.printStackTrace ();} Q-||A  
catch(Exception e){e.printStackTrace ();} Q57Z~EsF  
} ?7w7Y;FuR  
$2$jV1s  
6bBNC2K$-  
private void processErrorCode(int nErrorCode) U sV?}  
{ B'D~Q  
System.err.println("Error Code : " + nErrorCode); zu``F]B  
} +3?.Vb%jY  
@gm!D`YL  
l/56;f\IA  
//停止文件下载 Bx0=D:j  
public void siteStop() _>G=xKA#e  
{ 2.&%mSN  
bStop = true; *r iWrG  
for(int i=0;i<nStartPos.length;i++) #Z}YQ $g  
fileSplitterFetch.splitterStop(); U (A#}  
ccgV-'IG9  
b`|,rfq^AZ  
} m<|fdS'@  
} S,RC;D7  
//负责部分文件的抓取 I<hMS6$<LE  
**FileSplitterFetch.java 7:wf!\@ I  
*/ 36yIfC,  
package NetFox; FK;2u $:  
M3H^s_  
v|2+7N:[;  
import java.io.*; Ol*|J  
import java.net.*; =${ImMwj  
# 0/,teJ k  
l,ra24  
public class FileSplitterFetch extends Thread { d 2z!i^:  
I3dUI~}u  
='fN xabB  
String sURL; //File URL me@EKspX  
long nStartPos; //File Snippet Start Position ]?~[!&h  
long nEndPos; //File Snippet End Position 1K[y)q  
int nThreadID; //Thread's ID -7A2@g  
boolean bDownOver = false; //Downing is over {Ty?OZ  
boolean bStop = false; //Stop identical 3s Mmg`  
FileAccessI fileAccessI = null; //File Access interface \n0MqXs#  
%?!TqJT?{  
Z+Ppd=||,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qz|xow/ns@  
{ qj,^"rp1:  
this.sURL = sURL; sKDL=c;?j  
this.nStartPos = nStart; JO\KTWtjO  
this.nEndPos = nEnd; 5} 1qo7;  
nThreadID = id; 5>~q4t)6z}  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >;k~B  
}  q #X[oVq  
\"$jj<gc  
.< -~k@ P  
public void run() x$6FvgP(  
{ P@Av/r  
while(nStartPos < nEndPos && !bStop) ` NWmwmWB"  
{ H:X(><J  
e)]DFP[ n  
/UiB1-*b  
try{ iI!g1  
URL url = new URL(sURL); YG>6;g)Zm  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0<]]q[pr  
httpConnection.setRequestProperty("User-Agent","NetFox"); -d6PXf5  
String sProperty = "bytes="+nStartPos+"-"; ]0 ;,M  
httpConnection.setRequestProperty("RANGE",sProperty); G3de<?K.[V  
Utility.log(sProperty); eLk:">kj  
}~! D]/B  
vf['$um  
InputStream input = httpConnection.getInputStream(); K2-nP2Go?  
//logResponseHead(httpConnection); 'o-J)+oa  
UUxP4  
,~7+r#q7  
byte[] b = new byte[1024]; .KF(_ 92  
int nRead; 'z">4{5  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "I JcKoB  
{ ?) FY7[x.  
nStartPos += fileAccessI.write(b,0,nRead); LH>h]OTQF  
//if(nThreadID == 1) \-I)dMm[  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;;n=(cM|z  
} /P/::$  
v#$}3+KVC  
&%@>S.  
Utility.log("Thread " + nThreadID + " is over!"); ' g Fewo  
bDownOver = true; RJLhR_t7n  
//nPos = fileAccessI.write (b,0,nRead); jN2Xoh9  
} T$s)aM  
catch(Exception e){e.printStackTrace ();} eEg> EI_U  
} /5C>7BC  
} +!<{80w  
jx8hh}C  
gEnc;qb  
//打印回应的头信息 r%^XOw<'  
public void logResponseHead(HttpURLConnection con) a,\GOy(q{  
{ +(vL ~  
for(int i=1;;i++) KPI[{T\`ZM  
{ >2;KPV0H  
String header=con.getHeaderFieldKey(i); G>W:3y  
if(header!=null) Q?-uJ1J  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); scR+F'M  
Utility.log(header+" : "+con.getHeaderField(header)); 30L/-+r1  
else N"/be  
break; =N{-lyr)  
} H9rZWc"*  
} qN6GLx%  
Oa -~}hN  
lK #~lC  
public void splitterStop() 2%t!3F:  
{ vmT6^G  
bStop = true; 2Jn?'76`  
} Zz56=ZX*_  
0p!N'7N  
\t]aBT,  
} "'mr0G9X  
_tVrLb7`s  
]=m0@JTbG  
/* j0IuuJ+  
**FileAccess.java !6{b)P  
*//文件访问(定位,写) >s"kL^  
package NetFox; &3'zG)  
import java.io.*; ?1lx8+  
N;XJMk_ H  
\DRYqLT`  
public class FileAccessI implements Serializable{ UQ)7uYQ5  
;X[23A{  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R=s^bYdoy  
RandomAccessFile oSavedFile; v9vY#W  
long nPos; u"M^qRhD  
k0!D9tk  
*(]@T@yN  
public FileAccessI() throws IOException Op:7EdT#  
{ ($:JI3e[;  
this("",0); =/F\_/Xw  
} S[o R q  
xm}`6B^f  
QzA/HP a  
public FileAccessI(String sName,long nPos) throws IOException 8rgNG7d  
{ J`{HMv  
oSavedFile = new RandomAccessFile(sName,"rw"); /A/k13 J  
this.nPos = nPos; Q OP8{~O  
oSavedFile.seek(nPos); Se&%Dr3Nv  
} AC/82$  
)ia$pe s  
d#wK  
public synchronized int write(byte[] b,int nStart,int nLen) 8sxH)"S  
{ ?u /i8  
int n = -1; { w:9w  
try{ _K|513I  
oSavedFile.write(b,nStart,nLen); ]mmL8%B@_  
n = nLen; NI% ()  
} @awN*mO  
catch(IOException e) &fWYQ'\>  
{ OL)M`eVQ'  
e.printStackTrace ();  p(Bn!  
} |p{FSS  
?$FvE4!n  
B|n<{g[-cM  
return n; /-jk_8@a  
} @^93q  
@Xe[5T  
FR@## i$  
} B|+tK  
S)d_A  
rJl'+Ae9N|  
/* Gn%gSH/  
**SiteInfoBean.java [sH[bmLR  
*/ JK9}Kb};  
package NetFox; YKs^aQm#  
:ift{XR'  
gAgP("  
public class SiteInfoBean { 4`+hX'  
0q ^dpM  
/R44x\nhr  
private String sSiteURL; //Site's URL [{!5{k!  
private String sFilePath; //Saved File's Path 1p9+c~4l:  
private String sFileName; //Saved File's Name }];_ug* "  
private int nSplitter; //Count of Splited Downloading File ^04|tda  
RW. >;|m  
/K]<7  
public SiteInfoBean() oZ(T`5  
{//nSplitter的缺省值为5 {|J'd+  
//default value of nSplitter is 5 E64d6z^7u  
this("","","",5); I*^3 Z  
} +e%U6&l{  
q^hL[:ms#  
<e&*Tx<8  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !xxu~j^T  
{ Z[{: `  
sSiteURL= sURL; 1RF? dv  
sFilePath = sPath; *@,>R6)jI  
sFileName = sName; m*S[oy&  
this.nSplitter = nSpiltter; =a .avOZ  
^J=l]  l  
xPi/nWl`|  
} `?ijKZ}y5  
\kGi5G]  
@n##.th  
public String getSSiteURL() /hMD Me  
{ 'M#'BQQ5  
return sSiteURL; 6M`N| %  
} Q+\?gU]  
D,rs)  
&L S&O  
public void setSSiteURL(String value) LGm>x  
{ -a[] #v9  
sSiteURL = value; v*7lJNN.  
} 75V?K  
>9.xFiq<  
fscAG\>8  
public String getSFilePath() 5/O;&[lYy  
{ $3Ct@}=n  
return sFilePath; I(dMiL  
} bNG;`VZ%  
Ge>%?\  
^{T3lQvt  
public void setSFilePath(String value) )c#m<_^  
{ ]jz%])SzH  
sFilePath = value; Ppzd.=E  
} H0 YxPk)  
bt,^-gt@  
&ns !\!  
public String getSFileName() 89@e &h*  
{ {g>k-.  
return sFileName; })R8VJ&C/  
} Tej-mr3P  
eswsxJ/!  
Jn>7MuG  
public void setSFileName(String value) `!j|Ym  
{ v^h \E+@  
sFileName = value; P/'~&*m-  
} cia4!-#  
I"]5B  
JxP=[>I  
public int getNSplitter() oA kF  
{ ?[K+Ym+  
return nSplitter; 3 G?^/nB  
} pH%cbBm  
Ab <4F 7  
-k p~p e*T  
public void setNSplitter(int nCount) D@i,dPz5Zl  
{ [UVxtMJ  
nSplitter = nCount; $C UmRi{T  
} |yi3y `f  
} Ok+zUA[Wu  
'|b {  
q9RCXo>Y+1  
/* T{={uzQeJJ  
**Utility.java u":D{+wC |  
*/ ^IxT.g  
package NetFox; B8^tIq  
,*2%6t`N?  
UlHRA[SCv  
public class Utility { zv]-(<B  
iAX\F`  
j w)Lofn  
public Utility() dUtxG ~9  
{ Y WSo:)LY  
pCz;km  
"msCiqF{z  
} x=yU }lsV  
x-0IxWD%  
//线程睡眠 )>atoA  
public static void sleep(int nSecond) Z1FO.[FV  
{ N7%+n*Z  
try{ 8u$Kr q  
Thread.sleep(nSecond); PXcpROg56  
} oW-Tw@D  
catch(Exception e) N 5rY*S  
{ cWl)ZE<hM  
e.printStackTrace (); (XJehdB0  
} JbG\Ywi0]  
} 0Ng6Xg(QHc  
Bo?uwi  
//日志 CJ_X:Frj)  
public static void log(String sMsg) ~4[2{M.0>@  
{ X6 ~y+ R  
System.err.println(sMsg); J p.Sow  
} jMUE&/k  
&J_|P43  
z12[vN  
public static void log(int sMsg) pr\yc  
{ kL^;^!Nt  
System.err.println(sMsg); )#MKOsOct  
} |2X Et\P  
} =YBwO. !%  
5M{N-L_eC  
lph3"a^  
/* -[s*R%w  
**TestMethod.java 0k>NuIIP  
*/ J={$q1@lq  
package NetFox; 7Nc@7_=  
_> .TB\  
6)P~3 C'  
public class TestMethod {  M}}9  
sMli!u  
M|FwYF^  
public TestMethod()  r_]wa  
{ ///xx/weblogic60b2_win.exe VG+Yhm<SL  
try{ B8 -/ C\  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3=) /-l  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z-uJ+SA  
SiteFileFetch fileFetch = new SiteFileFetch(bean); zzuDI_,/  
fileFetch.start(); B4R!V!Z*  
} *#Hi W)  
catch(Exception e){e.printStackTrace ();} ]c+qD,wqt>  
iwCnW7:  
Es zwg  
} 8[,,Kr)-  
A$A7 F=x  
 2 Ua_7  
public static void main(String[] args) \P!v9LX(  
{ a2UER1Yp"  
new TestMethod(); 7i~::Z <  
} g8mVjM\B;  
} [+gX6  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八