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
  • 8650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
/* 3a#X:?  
**SiteFileFetch.java hCXSC*;  
*/ ]WLQ q4q  
package NetFox; m$glRs @  
import java.io.*; jET$wKw%  
import java.net.*; N 6CWEIJ  
iCA!=%M@D  
C'~K amS  
public class SiteFileFetch extends Thread { ~pM\]OC  
_"BYnPq@wb  
{O\>"2}m'f  
SiteInfoBean siteInfoBean = null; //文件信息Bean V?KACYd@O  
long[] nStartPos; //开始位置 t{)Z$ )'  
long[] nEndPos; //结束位置 9rhIDA(wc  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 N^,@s"g  
long nFileLength; //文件长度 kz4d"bTb  
boolean bFirst = true; //是否第一次取文件 %3v:c|r  
boolean bStop = false; //停止标志 {P'TtlEp  
File tmpFile; //文件下载的临时信息 B+e$S%HV  
DataOutputStream output; //输出到文件的输出流 u$T`Bn  
Vp3r  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) |Ld/{&Qr  
public SiteFileFetch(SiteInfoBean bean) throws IOException vfb~S~|U6g  
{ ?~G D^F  
siteInfoBean = bean; zk)9tm;i{  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Q_p!;3  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 7D5;lM[_  
if(tmpFile.exists ()) v0pyyUqS  
{ pz'l9Gp;@  
bFirst = false; \etuIFQ#U  
read_nPos(); hD OEJ  
} g? 7%  
else 7MX nt5qUh  
{ /SLAg&  
nStartPos = new long[bean.getNSplitter()]; e_Cns&  
nEndPos = new long[bean.getNSplitter()]; HS1Gy/6'  
} ` oBlv  
"S$4pj`<  
x,kZ>^]&b  
Z#8O)GK  
} Y yI4T/0s_  
ZY%]F,Y  
,,*i!%Adw  
public void run() >3R%GNw  
{ XhF7%KR  
//获得文件长度 V{51wnxT  
//分割文件 lZpa)1.tiC  
//实例FileSplitterFetch Ave{ `YD  
//启动FileSplitterFetch线程 Z1V%pg>]*  
//等待子线程返回 3:q\]]]S  
try{ %m8;Lh- X  
if(bFirst) PFP/Pe Ng;  
{ )ESF)aKMiz  
nFileLength = getFileSize(); 5o2W[<%v  
if(nFileLength == -1) TF)OBN~/  
{ wd4wYk\  
System.err.println("File Length is not known!"); h/9{E:ML  
} .gmNE$d  
else if(nFileLength == -2) l.tNq$3pS  
{ 6mH0|:CsY  
System.err.println("File is not access!"); 6>I{Ik@>  
} aOWE\I c8  
else H^Th]-Zl  
{ 2LpJxV  
for(int i=0;i<nStartPos.length;i++)  ZzDE  
{ y  @&Cn  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); rh;@|/<l  
} n<C4-'^U[a  
for(int i=0;i<nEndPos.length-1;i++) #lA8yWxr  
{ & w{""'  
nEndPos = nStartPos[i+1]; XqD/~_z;  
} }*+?1kv  
nEndPos[nEndPos.length-1] = nFileLength; 'BE &lW  
} {Vz.| a[T  
} I?sA)!8  
2{t i])  
U1&pcwP  
//启动子线程 J \iyc,M<M  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mp2J|!Lx  
for(int i=0;i<nStartPos.length;i++) eT??F  
{ vB0O3]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'qRK6}"T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >UTAk  
nStartPos,nEndPos,i); @^Tof5?F?  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l#8SlRji  
fileSplitterFetch.start(); tz(\|0WDQ  
} !2dA8b  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u(ep$>[F#_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]lj,GD)c  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9Vp|a&Ana  
nEndPos = " + nFileLength); vfG4PJ 6  
// fileSplitterFetch[nPos.length-1].start(); _C` cO  
F<8Rr#Z  
Ax[!7~s  
//等待子线程结束 Vmj7`w&  
//int count = 0; % j],6wW5J  
//是否结束while循环 L%,tc~)A  
boolean breakWhile = false; $+` YP  
RhM]OJd'  
o XA3 i  
while(!bStop) |1d;0*HIgX  
{ v ?b9TE  
write_nPos(); ,o(7z^1Pe;  
Utility.sleep(500); kz]vXJ  
breakWhile = true; z@E-pYV  
Pkx*1.uo  
57/9i> @  
for(int i=0;i<nStartPos.length;i++) x\qS|q\N  
{ G([8Q8B4 +  
if(!fileSplitterFetch.bDownOver) _D9` L&X}  
{ ^4@~\#$z  
breakWhile = false; vywd&7gK  
break; Do@:|n  
} \VL[,z=q.  
} i~\fpay  
if(breakWhile) -uZ bVd  
break; +QNFu){G  
$~UQKv>  
AJ-p|[wPz  
//count++; "kC uCc  
//if(count>4)  |*079v  
// siteStop(); [t55Kz*cD  
} 5ru&In&  
C2GF N1i  
I8r5u=PH  
System.err.println("文件下载结束!"); s^KUe%am0  
} HC,YmO:df"  
catch(Exception e){e.printStackTrace ();} 1 h(oty2p  
} uWw4l"RK`  
Skgvnmk[U  
+5pK[%k  
//获得文件长度 TK.a6HJG  
public long getFileSize() (fON\)l  
{ [;M31b3  
int nFileLength = -1; d%l_:M3  
try{ ne nYP0  
URL url = new URL(siteInfoBean.getSSiteURL()); 2`(-l{3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q1j<p)(  
httpConnection.setRequestProperty("User-Agent","NetFox");  /1-  
jbQ2G|:Q  
%MyA;{-F6  
int responseCode=httpConnection.getResponseCode(); @MIBW)P<  
if(responseCode>=400) jRN*W2]V  
{ 0ra VC=[  
processErrorCode(responseCode); UkrqHHpy  
return -2; //-2 represent access is error ]_NN,m>z  
} "oZ]/(  
%FnaS u  
m%ZJp7C  
String sHeader; J_tj9+r^  
&.ZW1TxE8  
1aKYxjYM  
for(int i=1;;i++) }5gAxR,  
{ )5Yv7x(K  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sGIY\%  
//Utility.log(in.readLine()); TQm x$  
sHeader=httpConnection.getHeaderFieldKey(i); "Y@rNmBj  
if(sHeader!=null) &Im{p7gf!b  
{ ")|3ZB7>*  
if(sHeader.equals("Content-Length")) WrhC q6  
{ +}c '4hRv  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4,L(  
break; IVD1 mk  
} Q!/<=95E  
} xlVQ[Mt  
else Eq-fR~< 9  
break; grEmp9Q ?  
} <{@?c  
} MdK!Y  
catch(IOException e){e.printStackTrace ();} .J' 8d"+  
catch(Exception e){e.printStackTrace ();} 4?XX_=+F|  
c^P8)g Pf  
_[8xq:G  
Utility.log(nFileLength); 87%t=X  
P9Hv){z  
^_b+o  
return nFileLength; .#R\t 7m%  
} 8 [i#x|`g  
vQ=W<>1   
\a+F/I$hwa  
//保存下载信息(文件指针位置) DX.u"&Mm  
private void write_nPos() F\ !;}z  
{ =W)Fa6P3j(  
try{ hGi"=Oud2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ay6G1\0W  
output.writeInt(nStartPos.length); CBx1.xL  
for(int i=0;i<nStartPos.length;i++) H=]$9ZH!  
{ >nmby|XtW  
// output.writeLong(nPos); E",s]  
output.writeLong(fileSplitterFetch.nStartPos); 5)4*J.  
output.writeLong(fileSplitterFetch.nEndPos); *leQd^47  
} 3/8o)9f.  
output.close(); DQW^;Ls  
} 6Uq@v8mh  
catch(IOException e){e.printStackTrace ();} quc?]rb  
catch(Exception e){e.printStackTrace ();} vPEL'mw/3#  
} 9Ue3 %?~c  
1 GUF,A+_O  
f XxdOn.  
//读取保存的下载信息(文件指针位置) sKIWr{D  
private void read_nPos() b?7?iV4  
{ uy\< t  
try{ T/G1v;]  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P\;lH"9  
int nCount = input.readInt(); B&A4-w v  
nStartPos = new long[nCount]; Mt)~:V+:  
nEndPos = new long[nCount]; 8'J> @ uW  
for(int i=0;i<nStartPos.length;i++) Wq 7 c/ |  
{ & Sy0Of  
nStartPos = input.readLong(); rb%P30qc4  
nEndPos = input.readLong(); 3:jKuOX  
} A<^IG+Q,B7  
input.close(); %Rv&VFg  
} BDZB;DPb  
catch(IOException e){e.printStackTrace ();} y %Get  
catch(Exception e){e.printStackTrace ();} W >eJGZ<  
} b_-ESs]g  
ju8tNL,J  
# 'G/&&<  
private void processErrorCode(int nErrorCode) Z@&_ T3M  
{ rz+G]J  
System.err.println("Error Code : " + nErrorCode); aB<~T[H%h  
} B, nCx=\S  
x3>K{  
CF9a~^+%  
//停止文件下载 dluNA(Xc-  
public void siteStop() T8>:@EL-k  
{ Fh& ` v0  
bStop = true; `g6XVa*%#  
for(int i=0;i<nStartPos.length;i++) w[\*\'Vm0  
fileSplitterFetch.splitterStop(); wl^bvHG  
4XK*sR0-`  
&W fs6g  
} t3u"2B7oG  
} bO1J#bcZ  
//负责部分文件的抓取 'p-jMD}O  
**FileSplitterFetch.java dgpo4'c}  
*/ I<|)uK7  
package NetFox; r<V]MwO=  
> C{^{?~u  
ElhTB  
import java.io.*; x*}j$n(Oa  
import java.net.*; `x$d8(1J`#  
`48jL3|  
xc Wr hg  
public class FileSplitterFetch extends Thread { M_+&XLnzsJ  
aq~hl7MTj  
W?~G_4  
String sURL; //File URL hXM8`iFW5  
long nStartPos; //File Snippet Start Position -h^FSW($-R  
long nEndPos; //File Snippet End Position )v;>6(  
int nThreadID; //Thread's ID ('Wo#3b$  
boolean bDownOver = false; //Downing is over w_pEup\`  
boolean bStop = false; //Stop identical 4>>{}c!nf  
FileAccessI fileAccessI = null; //File Access interface F6h3M~uR  
*c7kB}/  
%]nY v#K  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @=`Dw/13  
{ ,0NVb7F;k  
this.sURL = sURL; rZ 9bz}K  
this.nStartPos = nStart; 2\l7=9 ]\3  
this.nEndPos = nEnd; Z"'rc.>a  
nThreadID = id; [VIdw 92  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^"v~hjM#  
} ,)'!E^n  
pSkP8'  ?  
-(~Tu>KaH  
public void run() 5^cPG" 4@  
{ !I]fNTv<  
while(nStartPos < nEndPos && !bStop) W=}l=o!G.  
{ p.TR1BHw  
5p"n g8nR  
xr?=gY3E;  
try{ u$[ '}z0:  
URL url = new URL(sURL); GZ/.eYE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0vmMNF  
httpConnection.setRequestProperty("User-Agent","NetFox"); cy*Td7)/  
String sProperty = "bytes="+nStartPos+"-"; >Mj :'  
httpConnection.setRequestProperty("RANGE",sProperty); ur={+0 y  
Utility.log(sProperty); 1c&/&6 #5  
y;Q_8|,F  
/:>qhRFJA:  
InputStream input = httpConnection.getInputStream(); U`K5 DZ~  
//logResponseHead(httpConnection); uzG<(Q pu  
1c~c_Cc4  
R"e~0WO  
byte[] b = new byte[1024]; SEXeK2v  
int nRead; O7ceSz  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [Av87!kJ!X  
{ J)A1`(x&T  
nStartPos += fileAccessI.write(b,0,nRead); 'e02rqip{  
//if(nThreadID == 1) 78#je=MDg  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #6fp "  
} !FipKX  
U4%d #  
GBu&2}  
Utility.log("Thread " + nThreadID + " is over!"); \:4WbM:B  
bDownOver = true; %\\l/{`eW  
//nPos = fileAccessI.write (b,0,nRead); E}c(4RY  
} c.m ' %4  
catch(Exception e){e.printStackTrace ();} +`kfcA#pi  
} {5 -4^|!  
} zCL/^^#  
[%YA42_`LD  
yeKzI~  
//打印回应的头信息 T9KzVxHp5  
public void logResponseHead(HttpURLConnection con) '[I_Iu#,  
{ 8HX(1nNj}  
for(int i=1;;i++) )+wBS3BC  
{ [|d:QFx  
String header=con.getHeaderFieldKey(i); wblEx/FqE^  
if(header!=null) "@W0Lk[  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gsI"G  
Utility.log(header+" : "+con.getHeaderField(header));  }XaO~]  
else 1d7oR`qr  
break; PP/M-Jql)  
} AnU,2[(  
} gQ.yNe  
~ 6 1?nu  
jU)r~QhN  
public void splitterStop() _zI9 5  
{ Fj"g CBaR  
bStop = true; Y4 ){{bEp  
} A|CW4f,  
dc5w_98o  
$6XSW  
} "w9`UFu%^e  
%lbSV}V)  
 IKKd  
/* L-^vlP)Vu  
**FileAccess.java 3^q,'!PfB  
*//文件访问(定位,写) yX$I<L<Suz  
package NetFox; %CfJ.;BDNE  
import java.io.*; { > {|3  
6LL/wemq  
gH Q[D|zu  
public class FileAccessI implements Serializable{ v#a`*^ ^  
M<r' j $g  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Zn1+} Z@I  
RandomAccessFile oSavedFile; .6xP>!E}Q  
long nPos; ,E3"Ai sI  
{r`l  
zwN;CD1  
public FileAccessI() throws IOException \U4O*lq  
{ VmF?8Vi4  
this("",0); 6b9Ddb*  
} JHwkLAuz  
&1%W-&bc6  
'j !!h4  
public FileAccessI(String sName,long nPos) throws IOException sDK lbb  
{ -. L)-%wIV  
oSavedFile = new RandomAccessFile(sName,"rw"); N $M#3Y;  
this.nPos = nPos; Z%D*2wm4  
oSavedFile.seek(nPos); Z_}vjk~s  
} 7e/Uc!&*  
>J[g)$,  
-\6tVF11z  
public synchronized int write(byte[] b,int nStart,int nLen) Ht5 %fcD  
{ ? 1?^>M  
int n = -1; j.uN`cU!  
try{ -i V&-oP  
oSavedFile.write(b,nStart,nLen); }el. qZ  
n = nLen; e7t).s)b{  
} +[UFf3(ON  
catch(IOException e) wA+J49  
{ @4B+<,i   
e.printStackTrace (); VW<s_  
} !X(Lvt/  
9.qIhg  
>>rW-&  
return n; ?t'ZX~k  
} 3q R@$pm  
Lt8chNi [  
XASoS5  
} lJi'%bOi  
4-eb&  
-9~kp'_a  
/* L5(rP\B  
**SiteInfoBean.java ' jZ2^  
*/ v!E0/ gD  
package NetFox; _J 6|ju\  
HelC_%#^  
c ^G\w+_  
public class SiteInfoBean { .6 !IO^`[  
&0K; Vr~D  
<&n3"  
private String sSiteURL; //Site's URL U u(ysN4`  
private String sFilePath; //Saved File's Path K$\az%NE  
private String sFileName; //Saved File's Name LG [ 2u  
private int nSplitter; //Count of Splited Downloading File ;9q3FuR  
YPDc /  
?1xBhKq  
public SiteInfoBean() 6TbDno/!'  
{//nSplitter的缺省值为5 F@kOj*5,[  
//default value of nSplitter is 5 U# ueG  
this("","","",5); d@b0z$<s  
} tE]g*]o  
,ZJI]Q=!  
COOazXtW  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?g}n$%*5y!  
{  @zEEX9U  
sSiteURL= sURL; _{8f^@I"+  
sFilePath = sPath; JS642T  
sFileName = sName; u'd+:uH  
this.nSplitter = nSpiltter; |b;}' *  
Q nDymVF  
q =b.!AZy  
} !aeL*`;  
;wbQTp2  
z tHGY  
public String getSSiteURL() ibl^A=  
{ }H?8~S =  
return sSiteURL; HPCzh  
} { Y|h;@j$  
oB-&ma[ZS  
pco~Z{n  
public void setSSiteURL(String value) Xl#vVyO  
{ 1(gb-u0  
sSiteURL = value; %/oOM\} ++  
} t^Aios~F  
Fla[YWS  
[@";\C_I  
public String getSFilePath() N;F1Z-9  
{ -3qB,KT  
return sFilePath; J{@gp,&e  
} PkLRQ}  
 &{7n  
::dLOf8o  
public void setSFilePath(String value) P~#!-9?  
{ =3{h9  
sFilePath = value; ~4U[p  50  
} '# "Z$  
C:hfI;*7  
>L$y|8 O  
public String getSFileName() s^^X.z ,  
{ 5w gtc~  
return sFileName; +#6WORH0S  
} Umm_FEU#]  
%bt2^  
R# 8D}5[&  
public void setSFileName(String value) e=%7tK*  
{ (gNI6;P;}  
sFileName = value; %\}|&z6  
} w(J-[t118  
TIW6v4  
zek\AQN  
public int getNSplitter() OZbwquF@  
{  elWN-~  
return nSplitter; )"m FlS<I  
} enF.}fo]  
Z"lL=0rY/  
\C ZiU3  
public void setNSplitter(int nCount) B+jT|Y'  
{ .!U `,)I  
nSplitter = nCount; XU2 HWa  
} nOkX:5  
} !}"npUgE  
]b'K BAMy  
iEr|?,  
/* ;G0~f9  
**Utility.java 5BS-q"  
*/ <.l5>mgkCw  
package NetFox; Y3-Tg~/~W  
eoR@5OA&  
C]W VH\P p  
public class Utility { ,'Y*e[  
N,(@k[uta  
|E53 [:p  
public Utility() !H~!i.m'-  
{ u7^Z7; J  
2N5 N^S  
D?}LKs[  
} HNY{%D  
r;y&Wa  
//线程睡眠 jS5e"LMIq  
public static void sleep(int nSecond) (+Gd)iO  
{ N?kXATB  
try{ c[sC 2  
Thread.sleep(nSecond); b[uTt'p}  
} UldKlQ8  
catch(Exception e) vW"x)~B  
{ }C/}8<  
e.printStackTrace (); plsf` a  
} V3yO_Iqa  
} D@[$?^H  
x)BG%{h  
//日志 dWR?1sV|e  
public static void log(String sMsg) n-Dr/c4  
{ 1Lqs>*  
System.err.println(sMsg); 6:v8J1G(<  
} i/C#fIB2  
QDBptI:  
bTA<AoW9="  
public static void log(int sMsg) aMm`G}9n  
{ &4O"Xs`ka  
System.err.println(sMsg); OMJr.u  
} ] X%bU*4  
} _]j=[|q 9  
cn<9!2a  
`WWf?g  
/* 4yQ4lU,r  
**TestMethod.java W;~^3Hz6  
*/ GY@Np^>[a  
package NetFox; 9rn!U2  
@F=ZGmq  
8}xU]N#EV  
public class TestMethod { EIEwrC  
{4}Sl^kn*  
V *S|Qy!p  
public TestMethod() @a%,0Wn  
{ ///xx/weblogic60b2_win.exe [DGq{(O  
try{ A"vI6ud>  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); - CM;sXq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qyt6+xL  
SiteFileFetch fileFetch = new SiteFileFetch(bean);  P/nXY  
fileFetch.start(); Sl:\5]'yJ  
} - /#3U{O  
catch(Exception e){e.printStackTrace ();} b'3#FI=:  
qbqJ1^!6R  
8 Sl[&  
} 0<nKB}9  
/RX7AXXB  
(C6Y*Zm\  
public static void main(String[] args) xS,):R  
{ d@C ;rzR  
new TestMethod(); ZJy D/9y  
} dH?pQ   
} uBl&|yvxB  
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:
10+5=?,请输入中文答案:十五