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
  • 7566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
/* l<>syHCH;L  
**SiteFileFetch.java Wl/oun~o  
*/ )q 8w+'z  
package NetFox; @@"}i7  
import java.io.*; ;!q _+P  
import java.net.*; +3dWnBg?  
qT$;ZV #  
Aw~ =U!  
public class SiteFileFetch extends Thread { rU=qr&f"B  
brx 7hI  
zc01\M  
SiteInfoBean siteInfoBean = null; //文件信息Bean J]yUjnQ[h  
long[] nStartPos; //开始位置 -~ \R.<+  
long[] nEndPos; //结束位置 `w` f[dU-  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 C#d .3t  
long nFileLength; //文件长度 [APwHIS  
boolean bFirst = true; //是否第一次取文件 VNBf2Va  
boolean bStop = false; //停止标志 %nk]zf..  
File tmpFile; //文件下载的临时信息 1G$fU zS  
DataOutputStream output; //输出到文件的输出流 ``$Dgj[  
E #q gt9  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 8[\F*H  
public SiteFileFetch(SiteInfoBean bean) throws IOException B +[ri&6X\  
{ M!Q27wT8 O  
siteInfoBean = bean; F6 ?4&h?n  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); <E/4/ ANN  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); s!(O7Ub  
if(tmpFile.exists ()) ?f f!(U  
{ 4r&DW'  
bFirst = false; kH/u]+_  
read_nPos(); W/DSj :  
} y.PWh<dI  
else }K':tX?  
{ Q#w mS&$f  
nStartPos = new long[bean.getNSplitter()]; &YC Z L  
nEndPos = new long[bean.getNSplitter()]; h_#x@p  
} }%Mj`Bh  
ix4O-o{  
<qJI]P  
FcVQ_6  
} P'%#B&LZo  
dO]N&'P7  
E-gI'qG\(  
public void run() {w:*t)@j  
{ U4)x"s[CP  
//获得文件长度 :0@R(ct;>  
//分割文件 /e5' YVP  
//实例FileSplitterFetch cq:<,Ke  
//启动FileSplitterFetch线程 zG-pqE6  
//等待子线程返回 fy9mS  
try{ 011 N  
if(bFirst) yvR3|  
{ `#@#e Z  
nFileLength = getFileSize(); 7QV@lR<C2R  
if(nFileLength == -1) )aSj!X'`;  
{  dpG l  
System.err.println("File Length is not known!"); <L'!EcHm%]  
} (5CdA1|  
else if(nFileLength == -2) QA|87alh  
{ = VIU  
System.err.println("File is not access!"); ~EIK  
} >-8r|};+  
else pHKcKqB*13  
{ (sM$=M<$  
for(int i=0;i<nStartPos.length;i++) Rhi`4wo0$  
{ @yV.Yx"p_  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); xXb7/.*qE  
} s Zn@ye^  
for(int i=0;i<nEndPos.length-1;i++) #/N;ScyUJT  
{ wFbw3>'a9  
nEndPos = nStartPos[i+1]; B:mtl?69g  
} &#/UWv}f 0  
nEndPos[nEndPos.length-1] = nFileLength; ^*?mb)  
} uwI$t[  
} ,:[\h\5m  
 9}-;OJe  
OQnb^fabY  
//启动子线程 &VPfI  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bi{G :xt  
for(int i=0;i<nStartPos.length;i++) 'kuLkM,  
{ LI}@qLe  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P~}Yj@2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8kdJ;%^N  
nStartPos,nEndPos,i); E+Eug{+  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +HDfEo T  
fileSplitterFetch.start(); Dpb prT7_  
} z:1"d R   
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R1cOUV,y[/  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $y$E1A6h+  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }1kZF{KD<[  
nEndPos = " + nFileLength); ;$.^  
// fileSplitterFetch[nPos.length-1].start(); Sdzl[K/}  
Kcu*Z  
MA1y@  
//等待子线程结束 j{$2.W$  
//int count = 0; GI5#{-)  
//是否结束while循环 V}aZ}m{J  
boolean breakWhile = false; n@=D,'cn  
Zjkg"  
\yhj{QS.k  
while(!bStop) @1vpkB~ w  
{ )z\ 73|w  
write_nPos(); cj;k{ Moc  
Utility.sleep(500); ^ *1hz<  
breakWhile = true; bHRRgR`,  
[QDM_n  
mS?W+jy%  
for(int i=0;i<nStartPos.length;i++) _aP 2gH  
{ cI\&&<>SlG  
if(!fileSplitterFetch.bDownOver) 2cQG2N2*  
{ fB= j51Lw  
breakWhile = false; frRO?  
break; v"YaMbu  
} D KRF#*[=d  
} /l` "@  
if(breakWhile) nV/;yl4e{  
break; sl_f+h0  
yvCX is  
h$)4%Fy  
//count++; "Z]z9(  
//if(count>4) LV8{c!"  
// siteStop(); P$v9  
} Ex+E66bE  
2l}H=DZV  
\C kb:  
System.err.println("文件下载结束!"); #BW:*$>}  
} B=)tq.Q7  
catch(Exception e){e.printStackTrace ();} tjJi|  
} , Y^GQ`~#  
)v+\1  
CwaW>(`v  
//获得文件长度 'M35L30  
public long getFileSize() M*Ri1   
{ m](q,65 2  
int nFileLength = -1; (mgv:<c;BA  
try{ ZC97Z sE  
URL url = new URL(siteInfoBean.getSSiteURL()); KkZS6rD\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :Izdj*HL;A  
httpConnection.setRequestProperty("User-Agent","NetFox"); %?PRBE'}'  
~j yl  
5Ve T8/7Q  
int responseCode=httpConnection.getResponseCode(); -eFq^KP2  
if(responseCode>=400) 8Z>=sUMQ  
{ \t ^9UN  
processErrorCode(responseCode); ,HwOMoP7  
return -2; //-2 represent access is error BM[jF=0  
} qS[KB\RN1  
j>)yV@g/  
J3y4 D}  
String sHeader; s >7(S%#N  
|W*i'E   
T7Qw1k  
for(int i=1;;i++) zRFvWOxC\  
{ )#v0.pE  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O0QK `F/)*  
//Utility.log(in.readLine()); MNocXK  
sHeader=httpConnection.getHeaderFieldKey(i); .9!?vz]1  
if(sHeader!=null) k? !'OHmBL  
{ \*\)zj*r  
if(sHeader.equals("Content-Length")) QygbfW6u  
{ PDhoCAh !  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HG&rE3@  
break;  lx&;?QQ  
} wqAj=1M\  
} c;7`]}fGu  
else VH6J @m  
break; h`pXUnEZ  
} &5Huv?^a'  
} 5^C.}/#>F  
catch(IOException e){e.printStackTrace ();} .NT9dX  
catch(Exception e){e.printStackTrace ();} F~x>\?iN  
z<,-:=BC"  
c63yJqiW  
Utility.log(nFileLength); 2Z7r ZjXW  
DgKe!w$  
m[D]4h9  
return nFileLength; tQ Ia6c4|  
} lR0WDJv  
NH;.!x q:  
DGO\&^GT^  
//保存下载信息(文件指针位置) fl o9iifZ  
private void write_nPos() O9R[F  
{ 9;tY'32/  
try{ ;0-Y),  
output = new DataOutputStream(new FileOutputStream(tmpFile)); e<r}{=1w  
output.writeInt(nStartPos.length); T[eb<  
for(int i=0;i<nStartPos.length;i++) !EB[Lut m  
{ #9(L/)^  
// output.writeLong(nPos); 3pjK`"Nmz\  
output.writeLong(fileSplitterFetch.nStartPos); %SJFuw"  
output.writeLong(fileSplitterFetch.nEndPos); 1Y{pf]5Wx  
} abkt&981K+  
output.close(); yR[htD`  
} d'2q~   
catch(IOException e){e.printStackTrace ();} I3d!!L2ma  
catch(Exception e){e.printStackTrace ();} _ cm^Fi5  
} `R,g_{M j  
Og<nnq  
!b8.XGo  
//读取保存的下载信息(文件指针位置) Q[MWzsx  
private void read_nPos() :bu]gj4e  
{ ><H*T{ Pg  
try{ M&^Iun  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1XJLGMW,  
int nCount = input.readInt(); pvYBhTz0  
nStartPos = new long[nCount]; 67A g.f6-  
nEndPos = new long[nCount]; `,$PRN"]  
for(int i=0;i<nStartPos.length;i++) }$Z0v`  
{ y-lBaTE9  
nStartPos = input.readLong(); dQJ)0!B  
nEndPos = input.readLong(); => X"  
} i^hEL2S/A  
input.close(); ")D5ulb\  
} UQ}#=[)2e  
catch(IOException e){e.printStackTrace ();} 89\DS!\x9  
catch(Exception e){e.printStackTrace ();} ' oS= d  
}  $M|  
?C(3TKH  
;- 6   
private void processErrorCode(int nErrorCode) kn&>4/')  
{ T1i}D"H %  
System.err.println("Error Code : " + nErrorCode); oyq9XW~ D  
} I8Q!`K J  
o e,yCdPs  
Xhp={p;  
//停止文件下载 ^~7ouA  
public void siteStop() 9z kRwrQ  
{ ]4eIhj?  
bStop = true; Eh&-b6:  
for(int i=0;i<nStartPos.length;i++) ~zhP[qA})  
fileSplitterFetch.splitterStop(); 5aJd:36I  
% 9} ?*U  
AI#.G7'O  
} "I0F"nQ  
} FgnPh%[u  
//负责部分文件的抓取 tO+Lf2Ni+  
**FileSplitterFetch.java ].HHTCD`c  
*/ D8f4X w}=  
package NetFox; si#1sdR  
raJv$P  
SSysOeD+  
import java.io.*; U o[\1)  
import java.net.*; ZK5 wZU  
#D-Ttla  
F}c}I8Ao  
public class FileSplitterFetch extends Thread { /q5!p0fH*  
;}}k*< Z  
'q\[aKEX=  
String sURL; //File URL J=6( 4>  
long nStartPos; //File Snippet Start Position KZGy&u >`  
long nEndPos; //File Snippet End Position rmJ`^6V  
int nThreadID; //Thread's ID NM+ (ss'  
boolean bDownOver = false; //Downing is over Sy"!Q%+ |  
boolean bStop = false; //Stop identical c0QKx=  
FileAccessI fileAccessI = null; //File Access interface 9wdl1QS  
A.cNOous|  
Td 5yRN! ?  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $[V-M\q  
{ PnZY%+[I  
this.sURL = sURL; #AF.1;(k  
this.nStartPos = nStart; _&e$?hY  
this.nEndPos = nEnd; 7'.]fs:  
nThreadID = id; ^NXxMC( e+  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]h%~'8g,  
} *AJYSa,z  
B3&C=*y  
{ep.So6  
public void run() )4^Sz&\  
{ S`pBEM  
while(nStartPos < nEndPos && !bStop) `y$@zT?j  
{ szGGw  
eXi}-~o  
4(&sw<k  
try{ w5;d/r<q  
URL url = new URL(sURL); p|Qn?^C:  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?H!QV;ku  
httpConnection.setRequestProperty("User-Agent","NetFox"); Igh=Z %  
String sProperty = "bytes="+nStartPos+"-"; Y3O/`-9i  
httpConnection.setRequestProperty("RANGE",sProperty); 3|PV.  
Utility.log(sProperty); _*++xF1  
th%T(D5n  
yq12"Rs  
InputStream input = httpConnection.getInputStream(); #Wq@j1?  
//logResponseHead(httpConnection); ''H;/&nDX  
t5k=ngA  
p4vX3?&1W  
byte[] b = new byte[1024]; <Yn-sH  
int nRead; =F09@C,  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }#2I/dn  
{ J+m1d\lBu  
nStartPos += fileAccessI.write(b,0,nRead); b}!T!IP}  
//if(nThreadID == 1) PO*0jO;%  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \.YJs"<3  
} oAgU rl;R  
I ;F\'P)e  
.*&F  
Utility.log("Thread " + nThreadID + " is over!"); &M7AM"9  
bDownOver = true; v9"03 =h  
//nPos = fileAccessI.write (b,0,nRead); +LF`ZXe8l  
} (BGflb  
catch(Exception e){e.printStackTrace ();} SW7AG;c=  
} 3;F up4!4}  
} ` >[Offhd  
cUr5x8<W).  
_ ($U\FW  
//打印回应的头信息 7{p6&xXx  
public void logResponseHead(HttpURLConnection con) ~p x2kHZ  
{ v;(k7  
for(int i=1;;i++) Bhk@0\a  
{ <OTx79m  
String header=con.getHeaderFieldKey(i); O? 0`QMY  
if(header!=null) q +!i6!6r  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gwDVWhq  
Utility.log(header+" : "+con.getHeaderField(header)); jD ?*sd  
else dH)\zCt  
break; IHv>V9yiG  
} t:YMF$Z  
} KM/c^ a4V  
Pr3>}4M  
OlM3G^1e1  
public void splitterStop() yM*_"z!L  
{ _8e0vi!~2  
bStop = true; GYtp%<<9;  
} ] QJ7q}  
l:*.0Tj  
{J-Ojw|Y b  
} >dnDN3x  
Q+*@!s  
/L=Y8tDt  
/* 7MIrrhk  
**FileAccess.java wZt2%+$6m  
*//文件访问(定位,写) MH=Ld=i  
package NetFox; >aT~ G!y  
import java.io.*; u5tUm  
M/kBAxNIC|  
5ljEh -  
public class FileAccessI implements Serializable{ Esf\Bo"  
aX? tnDv  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P>'29$1'  
RandomAccessFile oSavedFile; Lc0=5]D   
long nPos; 6Oy6r  
4jW <*jM  
{/i&o  
public FileAccessI() throws IOException ;_m; :<  
{ mpD[k9`x#  
this("",0); lS?#(}a1)  
} [0lO0ik>G  
.:=5|0m  
!UHX? <3r  
public FileAccessI(String sName,long nPos) throws IOException \{= {{O  
{ fa!8+kfi  
oSavedFile = new RandomAccessFile(sName,"rw"); >^D5D%"  
this.nPos = nPos; FY pspv?4  
oSavedFile.seek(nPos); V^_U=Ed@M  
} #lF 2q w  
WTu!/J<\  
dte-2?%~j  
public synchronized int write(byte[] b,int nStart,int nLen) 8d(l)[GZt  
{ oo|Nu+  
int n = -1; K+`deH_d  
try{ } wx(P3BHD  
oSavedFile.write(b,nStart,nLen); I2z6iT4nB  
n = nLen; $?u LFD  
} oG c9 6B%  
catch(IOException e) " Rn@yZV  
{ UQjYWXvi  
e.printStackTrace (); pW_mS|  
} *A0*.>@N  
`E |>K\  
nI/kX^Pd  
return n; L$ZsNs+  
} 9[h8Dy  
N'Vj& DWC  
1z_1Hl  
} e^UUR-K%  
9r ](/"=f  
W Haf}.V  
/* Qjmo{'d  
**SiteInfoBean.java Qe`Nb4xf  
*/ b^"mQ   
package NetFox; TWdhl9Ot  
Tn?D~?a*O  
Z9i~>k  
public class SiteInfoBean { e^v\K[  
cCcJOhk|d  
j9.%(*  
private String sSiteURL; //Site's URL iYGa4@/uM  
private String sFilePath; //Saved File's Path r|y\FL  
private String sFileName; //Saved File's Name n<ecVFft  
private int nSplitter; //Count of Splited Downloading File E5\>mf ,;u  
L;fz7?_j  
B.~[m}  
public SiteInfoBean() rdH^"(  
{//nSplitter的缺省值为5 ?(M]'ia{  
//default value of nSplitter is 5 G> s qfYkK  
this("","","",5); O6ltGtF  
} sn+ kFvk}S  
+ZkJ{r0,(  
IiV]lxiE]  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QT4vjz+|  
{ 6t gq.XL^n  
sSiteURL= sURL; a!.Y@o5Ku  
sFilePath = sPath; /*G bl  
sFileName = sName; z6fY_LL  
this.nSplitter = nSpiltter; yF-`f _  
3dgPP@7d$  
 KON^  
} Rb0{W]opt+  
a..LbQQ  
KBA& s  
public String getSSiteURL() Z>*a:|  
{ 8v6AfTo%  
return sSiteURL; Q1!+wC   
}  {IT xHt  
f]2;s#cu  
|#Q0UM|'Q  
public void setSSiteURL(String value) EmyE%$*T  
{ 1w+)ne_&  
sSiteURL = value; gFXz:!A  
} 31N5dIi,  
[Bj\h7 G  
w8F`RRHEE  
public String getSFilePath() 'fZ\uMdTx  
{ hJ?PV@xy  
return sFilePath; ^~s!*T)\  
} H-eHX3c7  
)U{\c2b  
hLT?aQLx  
public void setSFilePath(String value) eL [.;_  
{ $)6x3&]P  
sFilePath = value; 7_J0[C!G  
} }/jWa |)f  
mNJCV8 <  
6UU<:KH  
public String getSFileName() 0JW =RW  
{ u.}H)wt  
return sFileName; <(1[n pS&+  
} (Mw+SM3<  
!1l~'/r  
I(b]V!mj:  
public void setSFileName(String value) NzS`s,N4/0  
{ ]$U A5/a  
sFileName = value; K*M1$@5  
} UD Pn4q  
h r6?9RJY  
(UZ].+)s  
public int getNSplitter() Sx1OY0)s  
{ "i&9RA! 1  
return nSplitter; f[?JLp   
} BC#O.93`  
(~fv;}}v  
ep{/m-h(!_  
public void setNSplitter(int nCount) Xm<|m#  
{ +]Ev  
nSplitter = nCount; DeI3(o7  
} u[nLrEnD  
} ^OK;swDW  
9zm2}6r4  
QkYKm<b  
/* NTVaz.  
**Utility.java 9)uJ\NMy  
*/ At&kW3(  
package NetFox; 8 EU/}Ym  
,x?Jrcx~'C  
< Yc)F.:  
public class Utility { -8v:eyc  
{: =]J4]  
D58RHgY[  
public Utility() 6_K7!?YG7  
{ AB<%GzW0(  
NHe[,nIV  
 3CPSyF  
} Hx n#vAc  
!t?5U_on  
//线程睡眠 |O;vWn'U2  
public static void sleep(int nSecond) R: [#OH.c  
{ H#G3CD2&  
try{ 7c8`D;A-K  
Thread.sleep(nSecond); u"8KH u5C@  
} #VxN [770  
catch(Exception e) <`NtTG  
{ t_+owiF)M  
e.printStackTrace (); yh'*eli  
} <v?2p{U%  
} y2R\SL,  
H|/"'t OZ  
//日志 VO /b&%  
public static void log(String sMsg) g+Y &rz  
{ a6?t?: ~|  
System.err.println(sMsg); { T<[-"h  
} {U4{v=,!I  
|hX\ep   
R7c42L\QA  
public static void log(int sMsg) D`U,T& @  
{ qC q?`0&#  
System.err.println(sMsg); n*Hx"2XF  
} @VyF' ?}  
} QHd|cg  
,rOh*ebF  
:d~mlyFI6P  
/* uc LDl  
**TestMethod.java \\{78WDA  
*/ %BQ?DTtb7'  
package NetFox; W,:j >v g  
09i7 7  
Vddod  
public class TestMethod { XANJA  
3ouo4tf$H.  
)JU`Z @?8  
public TestMethod() rS+ >oP}  
{ ///xx/weblogic60b2_win.exe olm'_ {{  
try{ ZgmK~iJ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {fY(zHC  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >y$*|V}k  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =E:sEw2j  
fileFetch.start(); 4b}'W}  
} NOf{Xx<#k  
catch(Exception e){e.printStackTrace ();} N:EljzvP}  
=6N=5JePB  
fc4jbPp:M  
} 3@* ~>H  
Iz&d S?p_  
?"kU+tCxg  
public static void main(String[] args) =@nW;PUZ  
{ G0Z$p6z  
new TestMethod(); @Ph'!  
} ]qx!51S  
} ^;$9>yi1  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八