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
  • 9519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
/* , `[Z`SUk`  
**SiteFileFetch.java + +T "+p  
*/ q#Yg0w~  
package NetFox; >%n8W>^^4  
import java.io.*; 33{;[/4  
import java.net.*; qXP1Q3  
7E!";HT  
M]6w^\4j9  
public class SiteFileFetch extends Thread { c]%;^)  
k Z+q  
zH=/.31Q  
SiteInfoBean siteInfoBean = null; //文件信息Bean vu_>U({. T  
long[] nStartPos; //开始位置 =A0"0D{\  
long[] nEndPos; //结束位置 @sB}q 6>  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 uS: A4tN  
long nFileLength; //文件长度 ?;:9 W  
boolean bFirst = true; //是否第一次取文件 ?8wwd!)x%  
boolean bStop = false; //停止标志 .*RB~c t  
File tmpFile; //文件下载的临时信息 F1?CqN M  
DataOutputStream output; //输出到文件的输出流 Ks49$w<  
d$"G1u~%  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) .KiPNTh'  
public SiteFileFetch(SiteInfoBean bean) throws IOException B%%.@[o,  
{ -(/2_&"  
siteInfoBean = bean; 3D?IG\3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); c]s (u+i  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); c ,h.`~{  
if(tmpFile.exists ()) eEWro F  
{ r%g <h T 8  
bFirst = false; E(aX4^]g  
read_nPos(); =1{H Sf  
} 7X9+Qj;  
else o ;[C(OS  
{ YiIddQ  
nStartPos = new long[bean.getNSplitter()]; ;1{iF2jZ:  
nEndPos = new long[bean.getNSplitter()]; %Lh-aP{[e  
} u|_LR5S!j  
kz7vbY  
RlI W&y  
e/]O<,*  
} dJdD"xj  
D_l/Gxdpr  
{+@ms$z  
public void run() QmWC2$b  
{ wo7N7R5  
//获得文件长度 AI^AK0.L  
//分割文件 6pM"h5hA  
//实例FileSplitterFetch W\I$`gyC/  
//启动FileSplitterFetch线程 4)z3X\u|Z2  
//等待子线程返回 i#L6UKe:Q  
try{ _9Dn \=g  
if(bFirst) " jl1.Ah  
{ {&\J)oZ  
nFileLength = getFileSize(); X;s 3y{ku  
if(nFileLength == -1) )^jQkfL  
{ ~=`f]IL  
System.err.println("File Length is not known!"); =,&u_>Dp  
} zVp[YOS&c  
else if(nFileLength == -2) jGk7=}nw  
{ o-\ok|,)#j  
System.err.println("File is not access!"); S KB@  
} 8eOl@}bV  
else (,- 5(fW  
{ g2[K<  
for(int i=0;i<nStartPos.length;i++) L0X&03e=e:  
{ *fxep08B  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 0=N4O!X9  
} 3gxf~$)?  
for(int i=0;i<nEndPos.length-1;i++) ~hS .\h  
{ K:}h\ In  
nEndPos = nStartPos[i+1]; (A7T}znG  
} M*g2VyZ  
nEndPos[nEndPos.length-1] = nFileLength; $x;tSJ)m~  
} i:l80 GK  
} httls>:xB|  
C!$Xv&"r  
S[-.tvI;Q  
//启动子线程 QT`fix{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pu\b`3C(  
for(int i=0;i<nStartPos.length;i++) 68v xI|EZ  
{ ?~F]@2)5w  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 06PhrPVa!\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?,WUJH?^  
nStartPos,nEndPos,i); DWF >b  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ::p-9F  
fileSplitterFetch.start(); iP~sft6  
} ,DE(5iDS  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'b LP ~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Eem 2qKj  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I x( 6  
nEndPos = " + nFileLength); ,$HHaoo g  
// fileSplitterFetch[nPos.length-1].start(); ,3G$`  
UqD5 A~w  
fdd~e52f  
//等待子线程结束 PLO\L W  
//int count = 0; "F&Tnhh4  
//是否结束while循环 b cC\  
boolean breakWhile = false; l9]o\JFXk  
|C~Sr#6)7  
l)}<#Ri  
while(!bStop) b2a'KczV  
{ 9U!JK3d  
write_nPos(); +ckMT3  
Utility.sleep(500); slu$2-H  
breakWhile = true; r`?&m3IOP  
0w^jls  
I|$'Q$m~  
for(int i=0;i<nStartPos.length;i++) V %i<;C  
{ Zk wJ.SuU  
if(!fileSplitterFetch.bDownOver) PqTYAN&F  
{ b OW}"  
breakWhile = false; uEBQoP2  
break; Xyb8u})p'  
} {\P?/U6~f  
} q A.+U:I8  
if(breakWhile) G"}qV%"6"  
break; )$MS 0[?  
[Dnusp7e  
RI?NB6U  
//count++; ;_x2 Ymw  
//if(count>4) C#Y,r)l  
// siteStop(); 4DvdE t  
} .8-PB*vb  
G?>qd}]y0L  
K3Huu!Tr  
System.err.println("文件下载结束!"); 2q+la|1Cr  
} DKR<W.!*t  
catch(Exception e){e.printStackTrace ();} OdO{xG G@  
} 4"LPJX)Q  
baqn7k"  
N[>:@h  
//获得文件长度 3QH(4N  
public long getFileSize() _\p`4-.V  
{ n1_ %Td  
int nFileLength = -1; @v"T~6M  
try{ STv(kQs  
URL url = new URL(siteInfoBean.getSSiteURL()); TV<Aj"xw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pH^ z  
httpConnection.setRequestProperty("User-Agent","NetFox"); b7Yq_%+  
L%f-L.9`u  
5Qb;2!  
int responseCode=httpConnection.getResponseCode(); %?@x]B9Y8E  
if(responseCode>=400) =1O?jrl~q  
{ AD(xaQ&T  
processErrorCode(responseCode); e,^pMg~  
return -2; //-2 represent access is error }Bd_:#.mw  
} 6{L F-`S%  
V!mWn|lf  
"@(58nk  
String sHeader; OO$|9`a  
OthG7+eF  
61G|?Aax  
for(int i=1;;i++) -H4PRCDH  
{ {d8^@UL  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k@7kNMl  
//Utility.log(in.readLine()); !!9{U%s  
sHeader=httpConnection.getHeaderFieldKey(i); u]R$]&<  
if(sHeader!=null) U8E0~[y'  
{ #0(fOHPQ  
if(sHeader.equals("Content-Length")) %t q&  
{ [ ynuj3G V  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >)4.$#H  
break; )4PB<[u  
} |%-YuD  
} Rb?~ Rs\  
else li@k Lh  
break; Ur n  
} t~q?lT  
} )TM!ms+K  
catch(IOException e){e.printStackTrace ();} M' YJ"  
catch(Exception e){e.printStackTrace ();} I`3d;l;d  
_n7%df  
h:_NA  
Utility.log(nFileLength); ~bWhth2*  
JXL'\De ;  
)t 5;d  
return nFileLength; >n(F4C-pl  
} s~=g*99H  
CNq[4T'~A  
f7ZA837Un  
//保存下载信息(文件指针位置) ZH!;z-R  
private void write_nPos() H)\4=^  
{ whw{dfE  
try{ v3~FR,Kl  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \PzN XQ$  
output.writeInt(nStartPos.length); NfOp=X?Y  
for(int i=0;i<nStartPos.length;i++) [Q|M/|mnR1  
{ 9Kx<\)-GMD  
// output.writeLong(nPos); 5 1"8Py  
output.writeLong(fileSplitterFetch.nStartPos); E3bwyK!s  
output.writeLong(fileSplitterFetch.nEndPos); ?H<~ac2e  
} \d:h$  
output.close(); loLKm]yV  
} }Iip+URG  
catch(IOException e){e.printStackTrace ();} uQWp+}>ZJy  
catch(Exception e){e.printStackTrace ();} 4AuH1m)<  
} Ep<YCSQy$i  
RU7!U mf  
9?$RO[vo  
//读取保存的下载信息(文件指针位置) x`#22"m  
private void read_nPos() ;c$@@ l  
{ 4? v,wq  
try{ ,! hnm  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \x(.d.l/  
int nCount = input.readInt(); UP?D@ogl<  
nStartPos = new long[nCount];  ; HP#bx  
nEndPos = new long[nCount]; 2p+C%"n>  
for(int i=0;i<nStartPos.length;i++) ^B|YO8.v  
{ -nOq\RYV  
nStartPos = input.readLong(); ] ;&"1A  
nEndPos = input.readLong(); ZOC#i i`:  
} >GmN~"iJ  
input.close(); QTfu:m{  
} &/iFnYVhy  
catch(IOException e){e.printStackTrace ();} >2u y  
catch(Exception e){e.printStackTrace ();} g9`[Y~  
} YQ+^  
-( (Z@T1k  
lYP~3wp99  
private void processErrorCode(int nErrorCode) s+'XQs^{aj  
{ UTvs |[  
System.err.println("Error Code : " + nErrorCode); !D7"=G}HD  
} BD4`eiu"  
#%4=)M>^  
&lq^dFP&Su  
//停止文件下载 gd_ ^  
public void siteStop() p0Z:Wkz]  
{ 8!;$qVt  
bStop = true; |UYED%dC  
for(int i=0;i<nStartPos.length;i++) Ox~ 9_d  
fileSplitterFetch.splitterStop(); l0. FiO@_Q  
bb}?h]a   
4QO/ff[ o  
} $e*B:}x}  
} 9{$8\E9*nd  
//负责部分文件的抓取 (uRZxX  
**FileSplitterFetch.java Fh^ox"3c  
*/ :pb67Al29  
package NetFox; ;$z7[+M  
3T?f5+@I  
'u1=XX h  
import java.io.*; +v!v[qn  
import java.net.*; Hsgy'X%om  
KxX[ S.C  
!VFem~'d  
public class FileSplitterFetch extends Thread { R5gado  
6< >SHw  
*%I[ ke *  
String sURL; //File URL 4~Dax)  
long nStartPos; //File Snippet Start Position `zY!`G  
long nEndPos; //File Snippet End Position DRp&IP<  
int nThreadID; //Thread's ID F3Ap1-%z  
boolean bDownOver = false; //Downing is over yjFe'  
boolean bStop = false; //Stop identical r ^ Y~mq  
FileAccessI fileAccessI = null; //File Access interface F3Dt7q  
ol<lCp  
A4 5m)wQ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Mc:b U  
{ 3p&jLFphL  
this.sURL = sURL; 7 v~ro  
this.nStartPos = nStart; ~#q;bS  
this.nEndPos = nEnd; ;:T9IL  
nThreadID = id; .&PzkqWZ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Je@kiE  
} kN.B/itvA  
^SAq^3^P!  
gApz:K[l  
public void run() _YLUS$Zw  
{ 'bPk'pj9  
while(nStartPos < nEndPos && !bStop) r@yD8D \  
{ ami09JHy  
Dkw*Je#6PX  
ED/FlL{  
try{ y1#O%=g  
URL url = new URL(sURL); \lW_f{X)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r :NH6tAL  
httpConnection.setRequestProperty("User-Agent","NetFox"); &XtRLt gS  
String sProperty = "bytes="+nStartPos+"-"; {_(+>v"eJ  
httpConnection.setRequestProperty("RANGE",sProperty); Zih ?Bm  
Utility.log(sProperty); lV)G@l[1  
 NpR6  
cQn)^jx=  
InputStream input = httpConnection.getInputStream(); [@|be.g  
//logResponseHead(httpConnection); {xToz]YA  
Ye@t_,)x  
$_FZn'Db6  
byte[] b = new byte[1024]; rVcBl4&1*g  
int nRead; np=kTJ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `iQqhx  
{ \K}aQKB/j  
nStartPos += fileAccessI.write(b,0,nRead); 8YKQIt K  
//if(nThreadID == 1) o:9$UV[  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B2(,~^39  
} 3S;N(A4  
cix36MR_  
"{ FoA3g|  
Utility.log("Thread " + nThreadID + " is over!"); ($S Lb6  
bDownOver = true; auL^%M|$R  
//nPos = fileAccessI.write (b,0,nRead); |Euus5[  
} K:_($X]  
catch(Exception e){e.printStackTrace ();} 0+j}};   
} [e1L{_*l  
} *KJ7nRKx(w  
Nxi)Q$  
ESv:1o`?n  
//打印回应的头信息 L/ fRF"V  
public void logResponseHead(HttpURLConnection con) VaJfD1zd1  
{ Onw24&  
for(int i=1;;i++) az2X ch]  
{ 0m&3?"5u  
String header=con.getHeaderFieldKey(i); ,E9d\+j  
if(header!=null) NnOI:X {  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gc,Ps  
Utility.log(header+" : "+con.getHeaderField(header)); 8^vArS;  
else P#*n3&Uu  
break; !.-.#<<_a  
} )8'jxiGs  
} 4| f}F  
`)tA YH  
PU Cx]5  
public void splitterStop() ~K` 1  
{ bjzx!OCpV  
bStop = true; Ow)R|/e /  
} R&Ci/  
no|Gq>Xp  
TY6 rwU  
} +N R n0 z(  
jyQVSQ s  
K(OaW)j  
/* Y 1y E  
**FileAccess.java K'Spbn!nC  
*//文件访问(定位,写) v20~^gKo=m  
package NetFox; SH=:p^J  
import java.io.*; =~J fVozU  
JO}?.4B  
tT-=hDw  
public class FileAccessI implements Serializable{ 9|3o<  
oIxH3T  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hVf^  
RandomAccessFile oSavedFile; ERC<Dd0  
long nPos; lwJipIO  
vi|Zit  
|_nC6 ;  
public FileAccessI() throws IOException +nQ!4  
{ <T4(H[9B  
this("",0); a.,i.2  
} ?0z)EPQ|  
f[}|rf  
<\ETPL,<  
public FileAccessI(String sName,long nPos) throws IOException 1Z 6SI>p  
{ !g2a|g   
oSavedFile = new RandomAccessFile(sName,"rw"); r0Z+ RB^I  
this.nPos = nPos; =YHt9fb$c  
oSavedFile.seek(nPos); j ug'g  
} j+Zt.KXjT  
#_fY4vEO  
?gG,t4D  
public synchronized int write(byte[] b,int nStart,int nLen) MD4\QNUa)*  
{ ^@"c`  
int n = -1; k>>`fE\K  
try{ \ 3G*j`  
oSavedFile.write(b,nStart,nLen); &k+*3.X  
n = nLen; ev"M;"y  
} r=$gT@  
catch(IOException e) WIG=D{\Yx  
{ Tq#<Po $  
e.printStackTrace (); -l JYr/MSL  
} xFwXW )  
27iy4(4  
_+n;A46  
return n; c'rd$  
} kwF]TO S  
[>p6   
b0YNac.l  
} \u8,!) 4i  
ttj2b$M,  
`:4MMr91  
/* 50,Y  
**SiteInfoBean.java O9*p0%ug  
*/ `p1DaV  
package NetFox; S+pP!YX  
\xeVDKJH+n  
k/bque  
public class SiteInfoBean { 6w!e?B2/%  
L=m:/qQL  
 "l2bx  
private String sSiteURL; //Site's URL ]#5^&w)'  
private String sFilePath; //Saved File's Path 5[<F_"x  
private String sFileName; //Saved File's Name OpqNEo\  
private int nSplitter; //Count of Splited Downloading File GA ik;R  
8f-:d]  
;dOs0/UM&  
public SiteInfoBean() Mciq-c)  
{//nSplitter的缺省值为5 Y }/c N\  
//default value of nSplitter is 5 |z+9km7,  
this("","","",5); kO+s+ 55  
} %YCd%lAe,  
VF= Z`  
<`+zvUx^?  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f?0D%pxc}&  
{ 1 7i$8  
sSiteURL= sURL; /x/4NeD  
sFilePath = sPath; ((cb4IX  
sFileName = sName; 6Hn)pD#U  
this.nSplitter = nSpiltter; m#MlH=-  
agW9Go_F[  
_uJVuCc  
} >HIt}Zh  
r`[B@  
0\wiam-  
public String getSSiteURL() B kV(81"C  
{ jN{Zw*  
return sSiteURL; 0d`5Gy_D%  
} M8zE3;5  
w%rg\E  
j8c6[ih  
public void setSSiteURL(String value) 3I\m,Ob  
{ [?I/Uo8  
sSiteURL = value; 3G.r-  
} B0"0_n7-  
0T0/fg(o  
_25d%Ne0  
public String getSFilePath() pI 5_Hg  
{ hb<k]-'!  
return sFilePath; Pxk0(oBX  
} *`1bc'umM;  
9t}J|09i  
A!4VjE>  
public void setSFilePath(String value) 5A,=vE  
{ 3`ml; L?D  
sFilePath = value; j[H0SBKC  
} Ge0Lb+<G  
=1/q)b,p)  
zv@bI~3~  
public String getSFileName() U3N(cFXn  
{ Th/{x h  
return sFileName; /ISLVp%H  
} Q ]0r:i= .  
Oa1'oYIHg  
eK *W =c#@  
public void setSFileName(String value) kXMP=j8  
{ >fg4x+0%  
sFileName = value; NhCAv +  
} s,kU*kHn  
}\VX^{K j  
cafsMgrA  
public int getNSplitter() }U i_ynZ!  
{ W6M jQ%f  
return nSplitter; vs\|rLa  
} jOv~!7T  
H@4/#V|Uy  
[n!x&f8Xh  
public void setNSplitter(int nCount) m\?\6W k  
{ E9L!)D]Y  
nSplitter = nCount; 4]IKh,jT  
} k{1b20  
} EP(Eq  
CdNih8uG  
^6#-yDZC@  
/* . wmkj  
**Utility.java jNIUsM 8e  
*/ j6}$+!E  
package NetFox; ~M; gM]r;  
s{B_N/^  
Wxc^_iqA1  
public class Utility { h&P {p _Y  
d "B5==0I  
La]4/=a  
public Utility() z 7@ 'CJ  
{ q}e]*]dJZ  
 +xq=<jy  
9GE]<v,_[  
} d9|T=R  
ve~C`2=;  
//线程睡眠 8lpzSJP4k  
public static void sleep(int nSecond) 0H<4+ *`K  
{ Z7oaQ\fR  
try{ @f%wd2  
Thread.sleep(nSecond); )lOji7&e  
} =nw0# '  
catch(Exception e) u X> PefR  
{ Q~b_dx{m  
e.printStackTrace (); boIVU`F-!  
} d _uF Y:  
} g*28L[Q~  
}`#B f  
//日志 BPqwDj W  
public static void log(String sMsg) YY\Rua/nG  
{ I0(8Z]x  
System.err.println(sMsg); a 1NCVZ  
} C?S~L5a#oC  
tbY  SK  
=:;YTie  
public static void log(int sMsg) RpjSTV8Tkm  
{ pb6 Q?QG,  
System.err.println(sMsg); Z+Xc1W^  
} OK.-]()!  
} }d@LSaM  
T6;>O`B.r  
P$Ax c/H  
/* FJW`$5?  
**TestMethod.java -h=c=P  
*/ ?f9$OLEB  
package NetFox; s 8Jj6V  
y6bjJ}  
Ty.drM  
public class TestMethod { }\U0[x#q  
5qeT4| Ol  
A xRl*B  
public TestMethod() ]yw_n^@  
{ ///xx/weblogic60b2_win.exe 2}597Hb   
try{ =[APMig,n  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F W/)uf3I  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A<a2TXcIE3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); t ]71  
fileFetch.start(); NavOSlC+h  
} < rv1IJ  
catch(Exception e){e.printStackTrace ();} j\nE8WH  
 Pb*q;9  
s8{-c^G:R  
} UP5%C;  
^GrNfB[Qu  
xu`d`!Tx  
public static void main(String[] args) Vvx a.B  
{ 'T6B_9GQ8  
new TestMethod(); Feh"!k <6k  
} kqQphKkL  
} B #;s(O  
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:
10+5=?,请输入中文答案:十五