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
  • 8075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
/* W2'!Pc,W  
**SiteFileFetch.java D}Sww5ZmP  
*/ h}kJ,n  
package NetFox; mhB2l/  
import java.io.*; ij;P5OA  
import java.net.*; 8|zOgn{  
c3r`T{Kf  
r-.>3J  
public class SiteFileFetch extends Thread { YrV@k*O*  
d</F6aM\  
nv\K!wZI=b  
SiteInfoBean siteInfoBean = null; //文件信息Bean Sa kew  
long[] nStartPos; //开始位置 CP0'pL=;  
long[] nEndPos; //结束位置 u1=K#5^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 216$,4i  
long nFileLength; //文件长度 [2h.5.af  
boolean bFirst = true; //是否第一次取文件 MdmN7>  
boolean bStop = false; //停止标志 8:> V'j  
File tmpFile; //文件下载的临时信息 X-#&]^d  
DataOutputStream output; //输出到文件的输出流 V1~@   
m xqY  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) <'N:K@Cs  
public SiteFileFetch(SiteInfoBean bean) throws IOException </u=<^ire  
{ *QV"o{V  
siteInfoBean = bean; p4 =/rkq  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,Vw>3|C  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); hS&l4 \I'Z  
if(tmpFile.exists ()) ncMzHw  
{ &} { #g  
bFirst = false; @\o"zU  
read_nPos(); I2Imb9k~B  
} iaLZ|\`3a  
else RB|i<`Z  
{ 8g Z)c\  
nStartPos = new long[bean.getNSplitter()]; @5ud{"|2  
nEndPos = new long[bean.getNSplitter()]; zo8D"  
} 1GqSY|FSGp  
Ka_;~LS>(  
P=_fYA3  
/KNDo^P  
} ^\&FowpP  
om2N*W.gk  
:mW< E  
public void run() bzxf*b1I  
{ 1m#.f=u{R  
//获得文件长度 P%gA` j  
//分割文件 EO~L.E%W  
//实例FileSplitterFetch bwH[rT!n  
//启动FileSplitterFetch线程 ~$J(it-a  
//等待子线程返回 ~UZ3 lN\E  
try{ a[ayr$Hk?  
if(bFirst) ^ nI2<P  
{ "r* `*1  
nFileLength = getFileSize(); Q;g7<w17  
if(nFileLength == -1) IWq#W(yM  
{ &N._}ts  
System.err.println("File Length is not known!"); JO+tY[q  
} &T~X`{V]`  
else if(nFileLength == -2) 9)NKI02M|  
{ EK Vcz'w  
System.err.println("File is not access!"); 0%dOi ko  
} N2"B\  
else bd~m'cob>  
{ w"wW0uE^  
for(int i=0;i<nStartPos.length;i++) b^Re947{g  
{ M/dgW` c  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @uldD"MJ<]  
} [ 'lu;1-,  
for(int i=0;i<nEndPos.length-1;i++) ^'0N%`bY!  
{ hlB\Xt  
nEndPos = nStartPos[i+1]; yDwh]t  
} WFh.oe8  
nEndPos[nEndPos.length-1] = nFileLength; 6#!CBY^{  
} $`55 E(  
} ^9:`D@Z+  
V5z2.} 'o-  
9$HBKcO  
//启动子线程 )c{>@WM~  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3ie k >'T  
for(int i=0;i<nStartPos.length;i++) RYjK4xT?Y/  
{ PPr Pj^%z=  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9K/EteS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),  2Y23!hw  
nStartPos,nEndPos,i); [I3Nu8  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5dI=;L >D  
fileSplitterFetch.start(); J\Pb/9M/  
} oDMPYkpTu  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XhHgXVVGG<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vxj:Y'}  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h_[{-WC  
nEndPos = " + nFileLength); }!oEjcX'  
// fileSplitterFetch[nPos.length-1].start(); !>n!Q*\(Ov  
b4i=%]v8  
XPO-u]<W  
//等待子线程结束 6]Hwr_/tk  
//int count = 0; 45 sEhs[$  
//是否结束while循环 TZ5TkE;1  
boolean breakWhile = false; 94BH{9b5  
={sjoMW  
uR5+")r@S  
while(!bStop) i[IFD]Xy!j  
{ Lo{wTYt:J  
write_nPos(); ou<3}g  
Utility.sleep(500); XGR2L DR  
breakWhile = true; t{jY@J T|  
b>OB}Is  
w\o6G7  
for(int i=0;i<nStartPos.length;i++) = IRot  
{ ! 6%?VJB|b  
if(!fileSplitterFetch.bDownOver) *VsVCUCz5*  
{ RI&O@?+U  
breakWhile = false; P'lnS&yA  
break; FL^ _)`  
} -&>V.hi7  
} 9 A ?{}c  
if(breakWhile) =wdh# {  
break; t.28IHJ  
U 5J _Y  
mG&A_/e!9  
//count++; W3tin3__  
//if(count>4) gHBvQ1g  
// siteStop(); 1fS&KO{a  
} :^3) [.m  
;rT'~?q  
cQj`W *  
System.err.println("文件下载结束!"); I"88O4\@  
} +9b{Y^^~T  
catch(Exception e){e.printStackTrace ();} KHML!f=mu  
} I.jqC2G  
S@HC$  
uI7n{4W*x  
//获得文件长度 |NZi2Bu  
public long getFileSize() v"o"W[  
{ Wn(!6yid  
int nFileLength = -1; U]sAYp^$  
try{ SWV*w[X<X  
URL url = new URL(siteInfoBean.getSSiteURL()); ~{/M_ =  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V2Vr7v=Y"  
httpConnection.setRequestProperty("User-Agent","NetFox"); PlzM`g$A  
^[x cfTN  
q5SPyfE[  
int responseCode=httpConnection.getResponseCode(); P[ :_"4U  
if(responseCode>=400) OB(o OPH  
{ 51q|-d  
processErrorCode(responseCode); u]IbTJ'  
return -2; //-2 represent access is error kWXLncE  
} PR.3EL  
,*XB11P  
Q%JI-&K  
String sHeader; ~Kw#^.$3T  
~V8z%s@  
#{q.s[g*+1  
for(int i=1;;i++) d2`g,~d  
{ @=Q!a (g  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XGx[Ny_A2  
//Utility.log(in.readLine()); o%t4WQ|bj  
sHeader=httpConnection.getHeaderFieldKey(i); 5CFNBb%Xy  
if(sHeader!=null) Qu61$!  
{ VV$t*9w  
if(sHeader.equals("Content-Length")) ,/{e%J  
{ k."p&  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \~ D(ww  
break; - eG~  
} %lHHTZ{+  
} H{*D c_  
else :25LQf^nz  
break; +lx& $mr?  
} 2 |je{  
} FOXSs8"c]!  
catch(IOException e){e.printStackTrace ();} 1#A$&'&\J;  
catch(Exception e){e.printStackTrace ();} ' P?h?w^T  
0kkDlWkzo  
=8\.fp  
Utility.log(nFileLength); ?R)]D:`  
P1-eDHYw  
bC<W7qf]}  
return nFileLength; HT;^u"a~  
} ]3_b3@k  
,;`f* #  
Y,}_LS$f  
//保存下载信息(文件指针位置) Jl/wP   
private void write_nPos() =fcg4h5(  
{ KxkBP/`3Q  
try{ b7QE  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Za:j;u Y  
output.writeInt(nStartPos.length); gg/`{  
for(int i=0;i<nStartPos.length;i++) cpQ5F;FI  
{ h[mT4 e3c  
// output.writeLong(nPos); xLW$>;kI  
output.writeLong(fileSplitterFetch.nStartPos); R/+$ :  
output.writeLong(fileSplitterFetch.nEndPos); v-1}&K  
} &xnQLz:#  
output.close(); vF27+/2+R  
} S+T/(-W  
catch(IOException e){e.printStackTrace ();} h aAY=:  
catch(Exception e){e.printStackTrace ();} ')"+ a^c  
} |?!i},Ki;  
&W2*'$j"_  
N6Mr#A-{  
//读取保存的下载信息(文件指针位置) IO\4dU)  
private void read_nPos() W7S~~  
{ FnO@\{M"A  
try{ UkL1h7}a\  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f<YYo  
int nCount = input.readInt(); Q\$3l'W  
nStartPos = new long[nCount]; <`}P  
nEndPos = new long[nCount]; <3;p>4gN  
for(int i=0;i<nStartPos.length;i++) n Nt28n@  
{ ~non_pJ  
nStartPos = input.readLong(); bKQho31a'  
nEndPos = input.readLong(); M-o'`e'  
} jxog8 E  
input.close(); |toP8 6  
} yb`PMjj15  
catch(IOException e){e.printStackTrace ();} y{ ur'**l  
catch(Exception e){e.printStackTrace ();} en<~_|J  
} b,xZY1a  
Xh9QfT,  
zPby+BP  
private void processErrorCode(int nErrorCode) =XP[3~  
{ kBo:)Vej4  
System.err.println("Error Code : " + nErrorCode); ?KC(WaGJQ  
} x)PW4{3qR  
\9?[|m z  
[9; @1I<x  
//停止文件下载 UqP{Cyy{  
public void siteStop() ]\(8d[ 4  
{ {&51@UX  
bStop = true; /(dP)ysc  
for(int i=0;i<nStartPos.length;i++) *1)>He$qL  
fileSplitterFetch.splitterStop(); GJ ^c^`  
./YR8#,  
}Hg G<.H>  
} @>2pY_  
} S_ATsG*(  
//负责部分文件的抓取 I?e5h@uE  
**FileSplitterFetch.java xRh 22z  
*/ Tgdy;?  
package NetFox; -k'<6op  
G@8)3 @  
y4^u&0}0$  
import java.io.*; G3.aw  
import java.net.*; xcB\Y:   
vSgT36ZF  
7Uenr9)M  
public class FileSplitterFetch extends Thread { t<H"J__&  
At Wv9  
@*6fEG{,q  
String sURL; //File URL \x<8   
long nStartPos; //File Snippet Start Position *6Wiq5M>.  
long nEndPos; //File Snippet End Position (V{/8%mWc  
int nThreadID; //Thread's ID 8Y($ F2  
boolean bDownOver = false; //Downing is over eADCT  
boolean bStop = false; //Stop identical Ca2r<|uA  
FileAccessI fileAccessI = null; //File Access interface LP vp (1  
EZUaYp ~M  
tB_le>rhl  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -&Rv=q>  
{ *;<fh,wOk  
this.sURL = sURL; qmrT d G  
this.nStartPos = nStart; _#8hgwf>  
this.nEndPos = nEnd; 3c<aI =$^  
nThreadID = id; 78& |^sq  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "5hk%T '  
} U&^q#['  
)jM%bUk,!  
8!_jZf8  
public void run() gQnr.  
{ 3jx%]S^z|  
while(nStartPos < nEndPos && !bStop) t~Q 9} +  
{ u?^V4 +V  
oRV}Nz7hr  
Rh=" <'d  
try{ e5L+NPeM6v  
URL url = new URL(sURL); l<=;IMWd  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 59E9K)c3  
httpConnection.setRequestProperty("User-Agent","NetFox"); I7ao2aS  
String sProperty = "bytes="+nStartPos+"-"; 1Bytu >2  
httpConnection.setRequestProperty("RANGE",sProperty); A  6(`  
Utility.log(sProperty); e" v%m 'G  
i5e10@Q{  
 o E+'@  
InputStream input = httpConnection.getInputStream(); q<YM,%mgj  
//logResponseHead(httpConnection); B%F]K<  
L}Z.FqJ  
*$Q>Om]  
byte[] b = new byte[1024]; iq&3S0  
int nRead; i<QDV W9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ptCF))Zm'  
{ \:vF FK4a  
nStartPos += fileAccessI.write(b,0,nRead); WogUILB  
//if(nThreadID == 1) c{q+h V=  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Fe~XO`  
} k8gH#ENNK  
&#p1ogf:  
At7!Pas#@g  
Utility.log("Thread " + nThreadID + " is over!"); omG2p  
bDownOver = true; &Vlno*  
//nPos = fileAccessI.write (b,0,nRead); eg[EFI.h  
} (:o F\  
catch(Exception e){e.printStackTrace ();} ^~4]"J};M  
} N?\X 2J1  
} (Y1*Bs[l  
<A3%1 82  
ni;_Un~  
//打印回应的头信息 ?ANW I8'_j  
public void logResponseHead(HttpURLConnection con) ~f<'] zXv  
{ ~k*]Z8Z  
for(int i=1;;i++) [ 8Ohg  
{ /!6'K  
String header=con.getHeaderFieldKey(i); 66=[6U9 *  
if(header!=null) %4~"$kE  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Jqoo&T")  
Utility.log(header+" : "+con.getHeaderField(header)); Yh<F-WOo2  
else )nm+_U  
break; 4n,&,R r#  
} K?.~}82c  
} V)$!WPL@  
C5~#lNC  
a&s34Pd  
public void splitterStop() !I7$e&Uz@  
{ ff--y8h  
bStop = true; iI GK "}  
} Aztrq  
F^dJ{<yX  
2BccE  
} WK%cbFq(  
XYcZ;Z9:  
g]~vZj  
/* j0l,1=^>l  
**FileAccess.java 1?'4%>kp  
*//文件访问(定位,写) (UkP AE  
package NetFox; pqG> |#RG  
import java.io.*; x@#>l8k?  
P\"kr?jZP  
T?3Q<[SmI  
public class FileAccessI implements Serializable{ J=A)]YE  
[S6u:;7  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fUw:jE xz  
RandomAccessFile oSavedFile; "Q:Gd6?h;  
long nPos; x^ s,<G  
f;E#CjlTL  
+d, ~h_7!  
public FileAccessI() throws IOException ieyK$q  
{ EX)&|2w  
this("",0); -}7$;QK&a  
} 7D'\z IW  
{"o9pIh{~  
*@rA7zPFf  
public FileAccessI(String sName,long nPos) throws IOException ]d*9@+Iu  
{ eMGJx"a  
oSavedFile = new RandomAccessFile(sName,"rw"); I~7iIUD  
this.nPos = nPos; 'F W?   
oSavedFile.seek(nPos); f3UCELJ  
} KhjC'CU,  
@IG's-  
!)a_@d.;i  
public synchronized int write(byte[] b,int nStart,int nLen) )fJ"Hq  
{ Du_5iuMh  
int n = -1; ay8]"sa  
try{ cAR `{%b  
oSavedFile.write(b,nStart,nLen); k*1Lr\1  
n = nLen; \M`qaFan5^  
} xe@e#9N$  
catch(IOException e) @eYpARF  
{ lZk  z\  
e.printStackTrace (); CE"/&I  
} .s{ "NqRA  
D||0c"E  
LOUP  
return n; BlJiHz!  
} p4T$(]7  
b0~r/M;J  
'_v~+  
} V%-hP~nyBx  
V60L\?a  
Q[OwP  
/* .`D'eS6b  
**SiteInfoBean.java ItVN,sVJb  
*/ mSYjc)z  
package NetFox; VMah3T!  
%lCZ7z2o  
H-_gd.VD  
public class SiteInfoBean { !Fl'?Kz  
g *$2qKm  
12`u[O}\}-  
private String sSiteURL; //Site's URL >axeUd+@i  
private String sFilePath; //Saved File's Path 3Gs\Q{O:  
private String sFileName; //Saved File's Name 3?o4  
private int nSplitter; //Count of Splited Downloading File KVZB`c$<t  
R3B+vLGX  
qO{z{@jo55  
public SiteInfoBean() ZthT('"a  
{//nSplitter的缺省值为5 JBY.er`6C  
//default value of nSplitter is 5 Nh\vWAz9  
this("","","",5); 'rhgM/I  
} Lu#qo^  
yTZev|ej@  
|))NjM'ZBl  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Lc!2'Do;  
{ }nrjA0WN  
sSiteURL= sURL; +&.zwniSS  
sFilePath = sPath; PVb[E03  
sFileName = sName; 0F[ f%2j  
this.nSplitter = nSpiltter; C m[}DB  
e:O,$R#g  
e)sR$]i:v  
} b 3x|Dq.  
Xs2}n^#i  
oSCaP,P  
public String getSSiteURL() Sa g)}6+  
{ W )FxN,  
return sSiteURL; ~qinCIj  
} 9c^,v_W@  
#/>TuJc  
um,f!ho-U  
public void setSSiteURL(String value) j_JY[sex  
{ Tpl]\L1v-  
sSiteURL = value; ggD T5hb  
} bRvGetX  
@&\Y:aRO%i  
K<P d.:  
public String getSFilePath() QFP9"FM5F  
{ f|{iW E2d  
return sFilePath; 868X/lL  
} s%:fZ7y  
j[U#J  
&g|[/~dIr  
public void setSFilePath(String value) -[=~!Qr:  
{ V'vWz`#  
sFilePath = value; `'1g>Ebk0  
} d]DV\*v  
|5 V0_79  
$toTMah w  
public String getSFileName() zu d_BOq{f  
{ >9H^r\  
return sFileName; NY7yk3  
} ? i _ACKpw  
sF{~7IB  
%,\JTN|g|A  
public void setSFileName(String value) J ?o  
{  qb? <u  
sFileName = value; 2+9VDf2  
} jR%*,IeB  
gG?@_ie  
7P1Pk?pxy  
public int getNSplitter() 4)gG_k  
{ x7S\-<8  
return nSplitter; !Gmnck&+  
} ~nA k-toJ  
O},}-%G  
ed6@o4D/kf  
public void setNSplitter(int nCount) re*}a)iL  
{ =Dn <DV  
nSplitter = nCount; !Se0&Ob  
} yCxYFi  
} B0Df7jr%`>  
LdZVXp^  
SA TX_  
/* ~P|;Y<?3  
**Utility.java ?~o`mg  
*/ #*g=F4>t  
package NetFox; j4/[Z'5ny  
s!IIvF  
3-/|G-4k7  
public class Utility { 0GUJc}fgvN  
|Y uf/G%/  
d"XZlEV  
public Utility() t'U=K>7  
{ C5~~$7k0  
;FqmZjm  
+[G9PP6  
} qHk{5O3  
zM0}(5$m  
//线程睡眠 sT?{  
public static void sleep(int nSecond) e"hfeNphz  
{ Uj5-x%~  
try{ h4]^~stI  
Thread.sleep(nSecond); gWr7^u&q@|  
} 'WW:'[Syn'  
catch(Exception e) @} Ig*@  
{ cQEUHhRg!  
e.printStackTrace (); Qj^Uz+b  
} CV0id&Nv  
} Lap?L/NS  
L"b&O<N o  
//日志 Bt<)1_  
public static void log(String sMsg) S)U*1t7[  
{ kp*v:*  
System.err.println(sMsg); I# tlaz#  
} CzBYH   
 ;+~5XLk  
.`IhxE~mN  
public static void log(int sMsg) Em!- W5*s  
{ E&8Nh J  
System.err.println(sMsg); )Q=u[ p  
} _*AI1/>`  
} %Xh}{o$G  
{4S UG o>  
&@lfr623  
/* e* [wF}))  
**TestMethod.java w-Ph-L/  
*/ xeF>"6\  
package NetFox; _}5vO$kdO  
$9YQ aN%  
Pxl,"  
public class TestMethod { :'T+`(  
QATRrIj{e  
Bc8&-eZ ,  
public TestMethod() J.UNw8z  
{ ///xx/weblogic60b2_win.exe {]\7 M|9\  
try{ naR<  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !Q>xVlPVu  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); { { \oC$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $UzSPhv[  
fileFetch.start(); EGl<oxL*R2  
} A}lxJ5h0  
catch(Exception e){e.printStackTrace ();} % mQ&pk  
as@8L|i*  
qxI $F  
} Ae7FtJO  
:of([e|u6  
H8YwMhE7  
public static void main(String[] args) DZqG7p$u4i  
{ Sn[xI9}O  
new TestMethod(); 6 ) i-S<(  
} K9@.l~n  
} 0h1u W26^  
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