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
  • 8730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
/* At"@`1n_u'  
**SiteFileFetch.java 7%C6gU!r  
*/ 6L8wsz CW  
package NetFox; 0DGXMO$;  
import java.io.*; T$SGf.-  
import java.net.*; }LOAT$]XI  
?v6xa Vg:  
B%[Yu3gBo  
public class SiteFileFetch extends Thread { [/'W#x  
oB+drDp8U  
x2 l~aw#?  
SiteInfoBean siteInfoBean = null; //文件信息Bean +dlN^P647  
long[] nStartPos; //开始位置 |'.\}xt7  
long[] nEndPos; //结束位置 w?Y;pc}1B  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 @2V#bK  
long nFileLength; //文件长度 ^`ny]3JA  
boolean bFirst = true; //是否第一次取文件 ?8pRRzV$  
boolean bStop = false; //停止标志 K;Fy&p^d  
File tmpFile; //文件下载的临时信息 L)kwMk  
DataOutputStream output; //输出到文件的输出流 :GK]"sNC  
uq'T:d  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) A3MVNz$wo"  
public SiteFileFetch(SiteInfoBean bean) throws IOException 86oa>#opU  
{ ?m0|>[j  
siteInfoBean = bean; SIVzc Hm  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); !ouJ3Jn   
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); sZ_+6+ :  
if(tmpFile.exists ()) CnN PziB  
{ ~8Z)e7 j  
bFirst = false; `C$.  
read_nPos(); ,-D3tleu`  
} Ns Pt1_ Y8  
else wMr*D['" #  
{ ve<D[jQsk  
nStartPos = new long[bean.getNSplitter()]; }Dp/K4  
nEndPos = new long[bean.getNSplitter()]; zr2oU '+  
} D&#wn.0|E  
'b~,/lZd  
OF-$*  
0F/o  
} >We4F2?  
.]24V!J(1w  
q-}q rg  
public void run() 4J{6Wt";  
{ R `  
//获得文件长度 c<Fr^8  
//分割文件 ^\KZE|^3@  
//实例FileSplitterFetch >8PGyc*9  
//启动FileSplitterFetch线程 -Q9} gaH_  
//等待子线程返回 d0YDNP%,_  
try{ <*oTVl4fS  
if(bFirst) lk;4l Z  
{ ir !/{IQx  
nFileLength = getFileSize(); x}B3h9]  
if(nFileLength == -1) bi~1d"j  
{ #TS:| =  
System.err.println("File Length is not known!"); 9vZ:oO  
} Lh\ 1L  
else if(nFileLength == -2) db#svj*  
{ x4v@o?zW  
System.err.println("File is not access!"); &L`^\B]k|  
} kn %i#Fz  
else <x-7MU&  
{ 9lqH  
for(int i=0;i<nStartPos.length;i++) (P'{A>aHl0  
{ Sq:,6bcG  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); l]R=I2t  
} 4]G J+a  
for(int i=0;i<nEndPos.length-1;i++) w#}[=jy  
{ )[wB:kG  
nEndPos = nStartPos[i+1]; QlE]OAdB42  
} L0.F }~S  
nEndPos[nEndPos.length-1] = nFileLength; *q;u%; 4  
} q{Ao j  
} k@Qd:I;;  
4ibOVBG:*,  
8Wba Hw_  
//启动子线程 F/ o }5H  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0@yw#.j  
for(int i=0;i<nStartPos.length;i++) G ,e!!J  
{ ULH<FDot  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9CG&MvF c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^ 6b27_=  
nStartPos,nEndPos,i); uA4x xY  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %0Ibi  
fileSplitterFetch.start(); !LM9  
} ~^bf1W[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "^Vnnb:Z*o  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #f@}$@  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m*|G 2  
nEndPos = " + nFileLength); NY?pvb  
// fileSplitterFetch[nPos.length-1].start(); \NZ@>on  
LNcoTdv}k  
{4{X`$  
//等待子线程结束 Q[Gs%/>  
//int count = 0; qnFg7X>C,  
//是否结束while循环 (3WK2IM^  
boolean breakWhile = false; %/2OP &1<  
-H F1c  
rn]F97v@]  
while(!bStop) b#-=Dbe  
{ tIk$4)ZAl  
write_nPos(); JFdMYb  
Utility.sleep(500); ?$MO!  
breakWhile = true; Rrrq>{D  
4-BrE&2f  
rgo!t028^  
for(int i=0;i<nStartPos.length;i++) j-d542"  
{ woa|h"T  
if(!fileSplitterFetch.bDownOver) 5 qMP u|A  
{ 1HLU &  
breakWhile = false; H#M;TjR  
break; @1~cPt   
} XVF!l>nE  
} 5Y 7 %Z  
if(breakWhile) m2HO .ljc  
break; OaKr_m  
tkQrxa|  
!yvw5As%  
//count++; Yfx?3  
//if(count>4) drvz [ 9;  
// siteStop(); HQSFl=Q  
} ,#bT  
^fV-m&F)K*  
\E6 0  
System.err.println("文件下载结束!"); {]%7-4E  
} -Un"z6*  
catch(Exception e){e.printStackTrace ();} uqVarRi$  
} CDY3+!  
3L-$+j~u  
'Z|Czd8E  
//获得文件长度 ^ U);MH8  
public long getFileSize() O;$}j:;KF  
{ p0D@O_ :5  
int nFileLength = -1; 8@ S@^C*F  
try{ y7,t "XV  
URL url = new URL(siteInfoBean.getSSiteURL()); L#WGOl  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "EVf1iQ  
httpConnection.setRequestProperty("User-Agent","NetFox"); '!`| H 3  
9rIv-&7'm  
ixL[(*V  
int responseCode=httpConnection.getResponseCode(); TEla?N  
if(responseCode>=400) ^x Z=";eq  
{ PzT@q\O  
processErrorCode(responseCode); --k!KrL  
return -2; //-2 represent access is error :Dfl,=S  
} x_9#:_S'  
ltyhYPS  
s )Xz}QPK.  
String sHeader; ']d(m?  
vsPIvW!V  
S_ra8HY8  
for(int i=1;;i++) !?sB=qo  
{ >`|Wg@_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <?:h(IZe[  
//Utility.log(in.readLine()); (1[Z#y[  
sHeader=httpConnection.getHeaderFieldKey(i); <nK@+4EH"o  
if(sHeader!=null) ~.#57g F"  
{ _bRgr  
if(sHeader.equals("Content-Length")) a5(9~. 9  
{ Z{gDEo)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |WNI[49  
break; F$'po#  
} KO/#t~  
} -c{Y+M`  
else '$VP\Gj.  
break; [+ : zlA  
} IR?nH`V  
} >QPCYo<E  
catch(IOException e){e.printStackTrace ();} ]bbP_n8  
catch(Exception e){e.printStackTrace ();} 3NdO3-~)  
$oJjgAxcZ  
#bCUI*N"P  
Utility.log(nFileLength); =@&>r5W1  
s@g _F  
7#N ?{3i  
return nFileLength; "Xl"H/3r  
} rHqP[[4B'  
a@AIv"q  
RjR+'<7E^  
//保存下载信息(文件指针位置) E>:#{%  
private void write_nPos() f%JM a]yV  
{ =BbXSwv'(  
try{ 8Pva]Q  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7jr+jNsowj  
output.writeInt(nStartPos.length); hu7o J H  
for(int i=0;i<nStartPos.length;i++) 2@Q5Ta #h  
{ +:Nz_l  
// output.writeLong(nPos); |,({$TrF  
output.writeLong(fileSplitterFetch.nStartPos); Y\ ;hjxR-  
output.writeLong(fileSplitterFetch.nEndPos); sLzZ}u?(  
} bM }zGFt  
output.close(); 2IP<6l8N  
} =$T[  
catch(IOException e){e.printStackTrace ();} TH55@1W,[  
catch(Exception e){e.printStackTrace ();} e.Q'l/g  
} ;iQw2XhT  
y-S23B(  
\?|^w.  
//读取保存的下载信息(文件指针位置) >>M7#hmt  
private void read_nPos() yTNHM_P  
{ IsVR4t]  
try{ YS<KyTb"  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }9N-2]  
int nCount = input.readInt(); W"\+jHF"  
nStartPos = new long[nCount]; of >  
nEndPos = new long[nCount]; ma/<#l^}  
for(int i=0;i<nStartPos.length;i++) r=xec@R]*  
{ ys:F  
nStartPos = input.readLong(); )`2ncb   
nEndPos = input.readLong(); - ^Y\'y2  
} :G=ol2Q  
input.close(); e&K7n@  
} r1z+yx  
catch(IOException e){e.printStackTrace ();} m:k;?p:x  
catch(Exception e){e.printStackTrace ();} *g9VI;X  
} R:+?<U&  
32pPeYxB!-  
bxWzm|  
private void processErrorCode(int nErrorCode) K.Cx 9  
{ [#AI!-  
System.err.println("Error Code : " + nErrorCode); 7\H_9o0$  
} 1c*:" k  
twt's,dO  
WpMm%G~'4t  
//停止文件下载 '5A&c(  
public void siteStop() _bv9/#tR  
{ z uo:yaO  
bStop = true;  B`vC>  
for(int i=0;i<nStartPos.length;i++) @PK 1  
fileSplitterFetch.splitterStop(); iQgr8[ SFf  
+ (`.pa z@  
Gz--C(  
} HcV,r,>e  
} &o&}5Aba9  
//负责部分文件的抓取 J<9}) m  
**FileSplitterFetch.java #%/Jr 52<  
*/ mi@uX@ #  
package NetFox; iszVM  
S2 P9C"  
LaL{ ^wP  
import java.io.*; rKTc 6h:)  
import java.net.*; f:AfMf>m  
X|4Kdi.r@  
B->oTC`5  
public class FileSplitterFetch extends Thread { ]<9o>#3  
kLXa1^Lq  
J:IAs:e`  
String sURL; //File URL A6xN6{R!  
long nStartPos; //File Snippet Start Position tItI^]w2s  
long nEndPos; //File Snippet End Position B"`86qc  
int nThreadID; //Thread's ID d6zq,x!cI  
boolean bDownOver = false; //Downing is over %][zn$aa|  
boolean bStop = false; //Stop identical hn$jI5*`  
FileAccessI fileAccessI = null; //File Access interface )/z+W[t  
l {\k\Q!4  
<! *O[0s  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @mcP-  
{ =`!# V/=  
this.sURL = sURL; \SWuylE  
this.nStartPos = nStart; RGBntp%  
this.nEndPos = nEnd; `2j"Z.=  
nThreadID = id; 3qDuF  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D}2$n?~+  
} <AHdz/N  
v5FfxDvw  
mAe)Hy %  
public void run() \=(U tro  
{ bE jQMlb  
while(nStartPos < nEndPos && !bStop) bOr6"nn  
{ hy3?.  
I@1VX5  
:Yi 4Ia  
try{ "msPH<D  
URL url = new URL(sURL); w-Q=oEt  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R78P](1\>  
httpConnection.setRequestProperty("User-Agent","NetFox"); ! OOOc  
String sProperty = "bytes="+nStartPos+"-"; /~g.j1g  
httpConnection.setRequestProperty("RANGE",sProperty); d:h X3  
Utility.log(sProperty); +('=Ryo T  
J|8 u  
g{hbq[>X]  
InputStream input = httpConnection.getInputStream(); D&6.> wt .  
//logResponseHead(httpConnection); #*  8^ar<  
kcP&''  
.|y{1?f_  
byte[] b = new byte[1024]; /f>I;z1  
int nRead; ;v ~xL!uQ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SPINV.  
{ cdg &)  
nStartPos += fileAccessI.write(b,0,nRead); b\xse2#  
//if(nThreadID == 1) b^<7@tY  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J& D0,cuk  
} j^Ln\N]^  
iUS?xKN$~-  
F[X;A\  
Utility.log("Thread " + nThreadID + " is over!"); ALKzR433/  
bDownOver = true;  >6'brb  
//nPos = fileAccessI.write (b,0,nRead); f=>ii v  
} V)mi1H|m  
catch(Exception e){e.printStackTrace ();} T 0?9F2  
} Pj7MR/AH  
} 1+ V<-I@{  
py\/m]  
wNl "y  
//打印回应的头信息 <7j"CcJzZ  
public void logResponseHead(HttpURLConnection con) GJBMaT  
{ K3`48,`?wA  
for(int i=1;;i++) %:Zp7O2UB'  
{ Lnl-han%  
String header=con.getHeaderFieldKey(i); {HP.HK  
if(header!=null) G+ NTn\  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7K/t>QrBtU  
Utility.log(header+" : "+con.getHeaderField(header)); ?T>NvKF  
else  s)9 sb J  
break; :(4];Va  
} i6k~j%0m  
} o H]FT{  
.j`8E^7<  
~0L:c&V  
public void splitterStop() ^C{?LH/2  
{ nyPW6VQ0n  
bStop = true; W\z<p P  
} uJJP<mDgA  
DjiWg(X  
=fI0q7]ndz  
} !6*4^$i#o  
q/3co86c  
?WrL<?r)}U  
/* inyS4tb  
**FileAccess.java ?MJ5GVeH  
*//文件访问(定位,写) w)Y}hlcq  
package NetFox; >soSOJ[   
import java.io.*; XQj+]-m  
wKy4Ic+RV  
P1"g62R  
public class FileAccessI implements Serializable{ \6,Z<.I  
^I!gteU;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t\lx*_lr  
RandomAccessFile oSavedFile; 7 '7a`-W  
long nPos; \3cg\Q+~  
OLDEB.@  
UG,n q  
public FileAccessI() throws IOException {ALOs^_-  
{ -V}ZbXJD  
this("",0); &fifOF#[ e  
} [&{NgUgu"  
_B\X&!G.  
#M8>)oc  
public FileAccessI(String sName,long nPos) throws IOException Jl89}Sf  
{ &3Mps[u:h  
oSavedFile = new RandomAccessFile(sName,"rw"); &sS]h|2Z5  
this.nPos = nPos; Y\{lQMCy  
oSavedFile.seek(nPos); 7 6S>xnN  
} /S%!{;:  
|r53>,oR<:  
6 ZVD<C:\  
public synchronized int write(byte[] b,int nStart,int nLen) |( R[5q  
{ ZRCUM"R_  
int n = -1; %l)~C%T  
try{ r A9Rz^;xa  
oSavedFile.write(b,nStart,nLen); z0 _/JwJn  
n = nLen; zKaEh   
} Redxg.P  
catch(IOException e) ^s?i&K,!  
{ {>.qo<k  
e.printStackTrace (); XO J@-^BX  
} L&~>(/*7U  
l,1.6  
iTeFy -Ct  
return n; 7R".$ p  
} C,3yu,'  
u9dL-Nr`  
JPS<e*5  
} \ffU15@N  
|-VbJd  
*wJ'Z4_5F  
/* ij1g2^],4  
**SiteInfoBean.java |} K7Q  
*/ `H\NJ,  
package NetFox; \fD[Ej  
~7&O[  
y1hJVYE2  
public class SiteInfoBean { .(zZTyZr  
7)a u#K6  
Cl3hpqv1I  
private String sSiteURL; //Site's URL c)=UX_S!  
private String sFilePath; //Saved File's Path [KwwhI@3  
private String sFileName; //Saved File's Name QjwCY=PK!  
private int nSplitter; //Count of Splited Downloading File {m<!-B95  
@GE:<'_:{  
0B~Q.tyP  
public SiteInfoBean() @7<m.?A!  
{//nSplitter的缺省值为5 >eaK@u-'0  
//default value of nSplitter is 5 JZrUl^8E  
this("","","",5); v4wXa:CJ  
} U HUO9h  
wenJ(0L|  
%uhhQ<zs%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RlTVx :  
{ )ur&Mnmm  
sSiteURL= sURL; zs@[!?A,  
sFilePath = sPath; d@t3C8  
sFileName = sName; $~*d.  
this.nSplitter = nSpiltter; MHKB:t]hA  
Gu9x4p  
)d-{#  
} EM.rO/qcW  
uDi#a~m@  
%uLyL4*L(p  
public String getSSiteURL() 9CTvG zkw  
{ A)q,VSR8  
return sSiteURL; 4lfJc9J  
} },LW@Z}  
K1>(Fs$  
Vl+,OBy  
public void setSSiteURL(String value) cZXra(AD  
{ 7%4@*  
sSiteURL = value; 1 +'HKT}  
} bwAL:  
& A<Pf.Us  
mF !=H%  
public String getSFilePath() CiGN?1|  
{ CVFsp>+  
return sFilePath; ~cEr <mzR  
} >K;'dB/m;1  
MhpR^VM'.  
q<cpU'-#  
public void setSFilePath(String value) vXM``|  
{ 3M&75OE  
sFilePath = value; L&nGjC+Lr  
} VCvqiHn  
oWUDTio#[  
{m%X\s;ni  
public String getSFileName() XP-4=0zd  
{ "ci<W_lx  
return sFileName; 'Kj8X{BSFb  
} oos35xV .  
5&r2a}K  
J ;wA  
public void setSFileName(String value) Ma3Hn  
{ dj76YK  
sFileName = value; 6gfdXVN5  
} qqYH}%0dz  
Up$vBE8i]  
k]`3if5>  
public int getNSplitter() []M+(8Z_P  
{ U q6..<#  
return nSplitter; n[/|M  
} %j=,c{`Q  
7>m#Y'ppl@  
+6{KrREX)  
public void setNSplitter(int nCount) ngJES` 0d  
{ oB$D&  
nSplitter = nCount; rkl/5z??  
} |7I.DBjR;  
} cZ7b$MZ%9  
-j9R%+YW<  
Q'^]lVY  
/* -~h2^Oez  
**Utility.java 6X:- Z 3  
*/ #| 8!0]n'  
package NetFox; Sk$ XC  
dR_hPBn/@  
)N2yhdcqI  
public class Utility { .n`MPx'  
k>Qr 14F  
pDlh^?cux  
public Utility() V@K}'f~  
{ <_H0Q_/(  
b`K~l'8  
T+2I:W%  
} ~4*9w3t   
[M2,bc8SJV  
//线程睡眠 p$@=N6)I.k  
public static void sleep(int nSecond) GKPqBi[rO  
{ /kVy#sT|  
try{ ?lU]J]  
Thread.sleep(nSecond); }~-)31e'`  
}  \'"q6y  
catch(Exception e) -zz9k=q  
{ ][bz5aV  
e.printStackTrace (); _ #l b\  
} );;UNO21+  
} eeb 8v:4  
# dxlU/*  
//日志 +.HQ+`8z]  
public static void log(String sMsg) .?S#DS )  
{ sa+:c{  
System.err.println(sMsg); :"O=/p+*Us  
} #D+Fq^="P  
6M$.gX G.  
Qq]UEI `Go  
public static void log(int sMsg) '7'cKp  
{ OG 5n9sx  
System.err.println(sMsg); &TWO/F+Y  
} !,\9,lc  
} QbqLj>-AJ  
:N)7SYQT  
Zml9 ndzT  
/* Ed*`d>  
**TestMethod.java [dU/;Sk5  
*/ ~5}b$qL#`  
package NetFox; =4JVUu~Z  
T:.J9  
n3b@ 6V1_  
public class TestMethod { cX.v^9kuX  
a/^Yg rC\T  
Punbw\9!d,  
public TestMethod() PD/JXExK  
{ ///xx/weblogic60b2_win.exe >cM U<'&  
try{ A7_*zR @  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l/rhA6kEU  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cB<0~&  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;co{bk|rj  
fileFetch.start(); D|-]"(2i  
} 1<5 9)RiO>  
catch(Exception e){e.printStackTrace ();} (%+DE4?  
^QW%< X  
R!pV`N  
} &<^@/osi  
!>S' eXt  
`&9#!T.  
public static void main(String[] args) V`fh,(:  
{ J;_JH lK  
new TestMethod(); nVyb B~.=  
} 9'5,V{pj  
} `8'T*KU  
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