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
  • 7545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
/* i: ZL0nH-  
**SiteFileFetch.java Q/,bEDc&  
*/ TFWx(}1  
package NetFox; p(F}[bP  
import java.io.*; =nYd|Ok  
import java.net.*; :|:Disg  
-H3tBEvoI  
(,gpR4O[  
public class SiteFileFetch extends Thread { +hIStA  
}!i#1uHUH:  
w< hw>e^.  
SiteInfoBean siteInfoBean = null; //文件信息Bean 9;^r  
long[] nStartPos; //开始位置 lKd+,<  
long[] nEndPos; //结束位置 \P;%fN  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 G' ~Z'  
long nFileLength; //文件长度 mOb*VH  
boolean bFirst = true; //是否第一次取文件 =Kv*M@  
boolean bStop = false; //停止标志 PSO9{!  
File tmpFile; //文件下载的临时信息 . _5g<aw;  
DataOutputStream output; //输出到文件的输出流 V^P]QQ\ )  
DB'd9<  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }jQxwi)  
public SiteFileFetch(SiteInfoBean bean) throws IOException "i\rhX  
{ ER O'{nT&  
siteInfoBean = bean; )5}=^aqd  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Nd.+Rs  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); gJ_{V;R  
if(tmpFile.exists ()) -Cjc~{B>7X  
{ 2Qqk?;^ 1  
bFirst = false; }hralef #N  
read_nPos(); 3TRzDE(J  
} zqDIwfW  
else gNdEPaaFI  
{ @hlT7C)xK  
nStartPos = new long[bean.getNSplitter()]; p9;Oe,Il  
nEndPos = new long[bean.getNSplitter()]; }dl[~iKW  
} |D %m>M6  
+0016UgS#  
NW'rqgG  
WB2An7i@"{  
} IcM99'P(  
L7*,v5  
R^PPgE6!$  
public void run() gAA2S5th  
{ 8,Jjv*  
//获得文件长度 HJVi:;o  
//分割文件 HuPw?8w=  
//实例FileSplitterFetch .Vm!Ng )j  
//启动FileSplitterFetch线程 >~-8RM  
//等待子线程返回 L> ehL(]!  
try{ #,0PLU3%  
if(bFirst) YRXXutm  
{ +*2]R~"M  
nFileLength = getFileSize(); $niJw@zC  
if(nFileLength == -1) zI5 #'<n  
{ y9cDPwi:b  
System.err.println("File Length is not known!"); 4+ BWHV  
} R36BvW0X  
else if(nFileLength == -2) :}\w2W E[  
{ >hkmL](^  
System.err.println("File is not access!"); qB57w:J  
} UQ;ymTqdc  
else ,m| :U  
{ zo,`Vibx<  
for(int i=0;i<nStartPos.length;i++) WoVPp*zlX  
{ M ABrf`<b  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); sb Wn1 T U  
} 9`P<|(  
for(int i=0;i<nEndPos.length-1;i++) G%{J.J41F  
{  |,*N>e  
nEndPos = nStartPos[i+1]; :+%"kgJNL  
} 4K_rL{s0U  
nEndPos[nEndPos.length-1] = nFileLength; 'Vwsbm tY  
} Zj@k3y  
} Arg604V3  
d"K~+<V}  
Zd~'%(q  
//启动子线程 .+|HJ(  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /5qeNjI+2  
for(int i=0;i<nStartPos.length;i++) !~+"TI}_%w  
{ 'R&Y pR  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WmO.&zp  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )-D{]>8  
nStartPos,nEndPos,i); C` s  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !c}?u_Z/  
fileSplitterFetch.start(); .<0|V  
} [{]/9E /&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5K_KZL-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N/wUP  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C|#GODA  
nEndPos = " + nFileLength); 42*y27Dtm  
// fileSplitterFetch[nPos.length-1].start(); :ud<"I]:  
0(!j]w"r3  
K`7(*!HEb  
//等待子线程结束 4+rr3 $AY  
//int count = 0; bXVH7Fy  
//是否结束while循环 /.54r/FN')  
boolean breakWhile = false; ZY_aE  
F E`4%X  
vL>cYbJ<  
while(!bStop) _[D6 WY+  
{ *C/bf)w  
write_nPos(); ,t"?~Hl".  
Utility.sleep(500); =<,>dBs}\  
breakWhile = true; yQAW\0`  
Y nD_:ZK  
:c4iXK0_^?  
for(int i=0;i<nStartPos.length;i++) %N jRD|  
{ (OA-Mgyc  
if(!fileSplitterFetch.bDownOver) ]>j>bHG  
{ OVwcjhQ  
breakWhile = false; /y8=r"'G  
break; #~3$4j2U(y  
} iME )Jl&  
} !V<c:6"  
if(breakWhile) vJybhdvP  
break; #%Z 0!  
3X &'hz@  
O!uZykdX4!  
//count++; K fM6(f:  
//if(count>4) <+7]EwVcn^  
// siteStop(); Ue:LKK1Gsr  
} vBFMne1h  
y {&"g  
M)m(  
System.err.println("文件下载结束!"); vy:-a G  
} GSHJ?}U,  
catch(Exception e){e.printStackTrace ();} %pikt7,Z~  
} (8JL/S;Z$  
Lek!5Ug  
7D5[ L  
//获得文件长度 ;k W+  
public long getFileSize() F0 .Rv):  
{ WruSL|4iH  
int nFileLength = -1; sBN"eHg  
try{ QcW6o,  
URL url = new URL(siteInfoBean.getSSiteURL()); , %8keGhl  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kGz0`8U Ru  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ox| ?  
O4)'78ATp  
}u3Q*oAGl  
int responseCode=httpConnection.getResponseCode(); ; 9n}P@  
if(responseCode>=400) P\jnht  
{ _*K=Z,a;\  
processErrorCode(responseCode); fT]hpoJl  
return -2; //-2 represent access is error Ch] `@(l  
} ,.<[iHC}9  
B=?m_4\$m  
=nVEdRU  
String sHeader; N7Kg52|  
hSl6 X3W  
O V"5:){  
for(int i=1;;i++) `;`fA|F^  
{ VVd9VGvh  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [6ycs[{!  
//Utility.log(in.readLine()); 4Nb&(p  
sHeader=httpConnection.getHeaderFieldKey(i); '' Pu  
if(sHeader!=null) U4$}8~o4  
{ Jw+k=>  
if(sHeader.equals("Content-Length")) tv]^k]n{rf  
{ Quq X4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i% FpPni  
break; =pT}]  
} `@_j Do  
} %qycxEVP  
else 0uZL*4A+C  
break; 8I>'x f  
} ??]b,f4CNa  
} %%-?~rjI  
catch(IOException e){e.printStackTrace ();} qsA`\%]H  
catch(Exception e){e.printStackTrace ();} u5'jIqlU  
@K=:f  
8|cQW-L  
Utility.log(nFileLength); q PveG1+25  
Qhc>,v)  
Ii.0Bul  
return nFileLength; OMY^'g%w  
} De<kkR{4  
d`w3I`P1  
'K!u}py  
//保存下载信息(文件指针位置) gN/kNck  
private void write_nPos() IYG,nt !  
{ S5+W<Qs  
try{ fb=[gK#*,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ku3(cb!2  
output.writeInt(nStartPos.length); -:V0pb  
for(int i=0;i<nStartPos.length;i++) hifC.guK  
{ E"'4=_  
// output.writeLong(nPos); (r9W[  
output.writeLong(fileSplitterFetch.nStartPos); }J^+66{  
output.writeLong(fileSplitterFetch.nEndPos); ZRy'lW  
} >)j`Q1Qc\  
output.close(); rOo |.4w  
} nb30<h  
catch(IOException e){e.printStackTrace ();} 0en Bq>vr  
catch(Exception e){e.printStackTrace ();} _xmS$z)TO  
} i-YSt5iq  
{<P{uH\l  
b(HbwOt ~3  
//读取保存的下载信息(文件指针位置) K ; e R)  
private void read_nPos()  Z,"f2UJ  
{ "9v4'"  
try{ ]aZ3_<b  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %wQE lkB  
int nCount = input.readInt(); qS!U1R?s  
nStartPos = new long[nCount]; q; ?Kmk  
nEndPos = new long[nCount]; />X"' G  
for(int i=0;i<nStartPos.length;i++) SZVAf|]Yg  
{ 7Eo;TNbb  
nStartPos = input.readLong(); <*3#nA-O>i  
nEndPos = input.readLong(); )JXlPU  
} c}G\F$  
input.close(); bH Nf>  
} 5OM*NT t  
catch(IOException e){e.printStackTrace ();} '89nyx&W  
catch(Exception e){e.printStackTrace ();} .At^b4#(  
} qa>H@`P  
~(x"Y\PEu  
EEp~\^ -  
private void processErrorCode(int nErrorCode) ra|Ku!  
{ 3 +WmM4|  
System.err.println("Error Code : " + nErrorCode); dr gCr:Gf  
} x:E:~h[.^  
([ODmZHv  
h|{DIG3  
//停止文件下载 CeINODcT  
public void siteStop() o:c:hSV  
{ MC~<jJ,  
bStop = true; O$(#gB'B  
for(int i=0;i<nStartPos.length;i++) QB<~+d W  
fileSplitterFetch.splitterStop(); M\D25=(  
x>Gx yVE  
9YvK<i&I  
} <i ";5+  
} 7?p>v34A  
//负责部分文件的抓取 Vv_lBYV  
**FileSplitterFetch.java  V$fn$=  
*/ s?7"iE  
package NetFox; }G ^nK m  
*cy!PF&  
1a tQ9  
import java.io.*; Zq"  
import java.net.*; &Vy.)0  
~F.kgX  
ZkqZO#nq C  
public class FileSplitterFetch extends Thread { *[+{KJ  
nU,~*Us  
^ 0g!,L  
String sURL; //File URL ?_j]w%Hz  
long nStartPos; //File Snippet Start Position 1xDh[:6  
long nEndPos; //File Snippet End Position q+U&lw|"w  
int nThreadID; //Thread's ID !%(PN3*  
boolean bDownOver = false; //Downing is over #:xv]qb`k  
boolean bStop = false; //Stop identical sP@7%p>wt  
FileAccessI fileAccessI = null; //File Access interface zI$'D|A  
YZZog6%  
/wPW2<|"X.  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .OZ\ s%h;  
{ !7n`-#)  
this.sURL = sURL; 6B!v;93U  
this.nStartPos = nStart; & R,QJ4L  
this.nEndPos = nEnd; 6$&%z Eh  
nThreadID = id; -u^f;4|u  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y-.aSc53  
} XaH;  
"V <WC"  
 NArr2o2  
public void run() xp F(de  
{ v!j%<H`NI  
while(nStartPos < nEndPos && !bStop) ?D+H2[n\a  
{ _BI[F m  
}=fls=c/0  
u,JUMH]@  
try{ 2. f8uq  
URL url = new URL(sURL); W=I~GhM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wrf+5 ;,,  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4l@aga  
String sProperty = "bytes="+nStartPos+"-"; 'kHa_  
httpConnection.setRequestProperty("RANGE",sProperty); Q#lFt,.y  
Utility.log(sProperty); Huc|HL#C  
Vx%!j&  
I_is3y0  
InputStream input = httpConnection.getInputStream(); q"u,r6ED  
//logResponseHead(httpConnection); oC}2 Z{  
L}VQc9"gc  
^+O97<#6C  
byte[] b = new byte[1024]; B=HE i\55K  
int nRead; A2''v3-h8  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 59H~qE1Md  
{ ~_|CXPiQ8  
nStartPos += fileAccessI.write(b,0,nRead); `k -|G2  
//if(nThreadID == 1) a,eEP43dn  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h|.{dv  
} !X\aZ{}Q  
d Z x  
->'xjD  
Utility.log("Thread " + nThreadID + " is over!"); '[p0+5*x  
bDownOver = true; U nS|""  
//nPos = fileAccessI.write (b,0,nRead); +&[X7r<  
} Z@i,9 a  
catch(Exception e){e.printStackTrace ();} km29]V=}  
} -/R?D1kOq  
} "DSRyD0M  
9P*p{O{_  
1"No~/_  
//打印回应的头信息 LJOJ2x  
public void logResponseHead(HttpURLConnection con) VgO.in^q  
{  #]J"j]L  
for(int i=1;;i++) f@ .s(i=z  
{ =D Tbz3<  
String header=con.getHeaderFieldKey(i); q>m[vvt"  
if(header!=null) gT2k}5d}p  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 22Oe~W;  
Utility.log(header+" : "+con.getHeaderField(header)); >NZJ-:t  
else il7gk<  
break; {-51rAyi  
} $AHdjQ[;6-  
} }CvhLjo  
cHon' tS  
6|Xm8,]yRw  
public void splitterStop() }'4aW_ta  
{ ;FnS=Z  
bStop = true; OE2r2ad  
} pE 6r7  
@;Xa&*   
GriFb]ml"  
} %JuT'7VB  
W];l[D<S*  
ivvm.7{  
/* lL*"N|Y  
**FileAccess.java v\R-G  
*//文件访问(定位,写) f`-UC_(;  
package NetFox; MS& 'Nj  
import java.io.*; Asli<L(?`  
9:7&`J lC#  
ddEV@2F  
public class FileAccessI implements Serializable{ G"U^ ]$(+K  
W_[ tdqey  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U,V+qnS  
RandomAccessFile oSavedFile; *rmM2{6  
long nPos; l8+;)2p!  
ft?c&h;At  
V"8w:?  
public FileAccessI() throws IOException R T/)<RT9  
{ ]%+T+ zg(Y  
this("",0); 3ZhuC".c  
} I~ e,']  
B>%;"OMp  
|9]_<X[ic  
public FileAccessI(String sName,long nPos) throws IOException 9lB$i2G>Zw  
{ ;]_h")4"c  
oSavedFile = new RandomAccessFile(sName,"rw"); g1&q6wCg|  
this.nPos = nPos; > mEB,  
oSavedFile.seek(nPos); vvF]g.,  
} 0?=a$0_C  
U<wM#l P|Z  
Jm,tN/o*  
public synchronized int write(byte[] b,int nStart,int nLen) &e99P{\D  
{ u6i X&%e  
int n = -1; )pG*_q  
try{ 98lz2d/Fcq  
oSavedFile.write(b,nStart,nLen); j>Cp4  
n = nLen; ,=dc-%J  
} g])iU9)8  
catch(IOException e) ,OBJ>_5  
{ .DHQJ|J-1  
e.printStackTrace (); mJ+mTA5bW  
} =}2k+v-B  
unt{RVR%  
P9 qZjBS  
return n; ;-8]  
} $tDM U3,W  
R,m|+[sl  
]p8<Vluv  
} 41I2t(H @z  
$8>II0C.  
t"X^|!hKIF  
/* [!U! Z'i  
**SiteInfoBean.java N_?15R7h  
*/ ?fQ8Ff  
package NetFox; ~r&+18Z;  
+Os9}uKf  
t<MO~_`!  
public class SiteInfoBean { !H~PF*,hY  
oq2-)F2/  
O8/r-?4.  
private String sSiteURL; //Site's URL ]4]AcJj  
private String sFilePath; //Saved File's Path EC7)M}H  
private String sFileName; //Saved File's Name n,`j~.l-=>  
private int nSplitter; //Count of Splited Downloading File N V`=T?1[5  
g:Ry.=F7W  
9}' 92  
public SiteInfoBean() 8@7leAq!  
{//nSplitter的缺省值为5 Pp`[E/ qj4  
//default value of nSplitter is 5 *&~ '  
this("","","",5); =" pNE#  
} WMnxN34  
X- `PF  
_Q7]Dw/w\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nf,Ez  
{ ;Hn>Ew  
sSiteURL= sURL; Ys8D|HIk  
sFilePath = sPath; ;:'ABfs  
sFileName = sName; j9&x# U  
this.nSplitter = nSpiltter; na_Wp^;  
t""d^a#Dp  
yQ| V7G  
} (1)b> 6  
lF~!F<^9  
R/l/GNm  
public String getSSiteURL() \ \gAa-}:  
{ -d^c!Iu|  
return sSiteURL; p$a+?5'Q  
} lf_q6y  
p_CCKU  
M2LW[z  
public void setSSiteURL(String value) yZ,S$tSR  
{ {VKP&{~O  
sSiteURL = value; "89L^I  
} ESnir6HoU  
>w#&fd  
%FLe@.Ep{D  
public String getSFilePath() bpdluWS+)  
{ rN`-ak  
return sFilePath; Vw5Pgtx  
} AA[?a  
K[i&!Z&  
<"nF`'olV  
public void setSFilePath(String value) (>`S{L C>s  
{ ]s` cn}d  
sFilePath = value; j<}y(~  
} 8?h&FbmB  
I36ClOG  
q0(-"}2l  
public String getSFileName() -* W\$ P  
{ '3 JVUHn  
return sFileName; Iy Vmz'  
} lQG;WVqW  
C5=m~  
[S?`OF12  
public void setSFileName(String value) Og?P5&C"9D  
{ 56H~MnX  
sFileName = value; oWBjPsQ  
} 0r]-Ltvl?}  
s"(F({J  
D'Uv7Mis  
public int getNSplitter() |v:fP;zc  
{ !jRs5{n^Ol  
return nSplitter; [>|6qY$D  
} Zz!yv(e)H  
 ,<U  
U[NQ"  
public void setNSplitter(int nCount) _ _[bKd.  
{ _m3#g1m{  
nSplitter = nCount; fT5vO.a  
} 8^hbS%s!  
} 0">9n9  
s(y=u>  
Q'0:k{G  
/* B0,C!??5  
**Utility.java +d=8/3O%  
*/ Y 9@ 2d  
package NetFox; XRXQ 7\n  
K.42 VM)F  
J['i  
public class Utility { Xe@:Aun  
ab>>W!r@!  
LNF|mS\+D  
public Utility() 7|X.E  
{ 4']eJ==OH  
7&1 dr  
=qS\+  
} ,AyQCUz{*?  
B4w/cIj_  
//线程睡眠 L+.-aB2!d  
public static void sleep(int nSecond) p s_o:*$l  
{ 7:n OAN}%  
try{ ~Q+J1S]Fs  
Thread.sleep(nSecond); @%I-15Jz  
} _o{w<b&  
catch(Exception e) rM)#}eZK!  
{ wPr!.:MF  
e.printStackTrace (); 5N$O  
} < [q{0,  
} sH :_sOV*  
fPab%>/T{  
//日志 @Mf ZP~T+  
public static void log(String sMsg) ML:H\  
{ !0Eo9bU%@  
System.err.println(sMsg); Qp~3DUM  
} /8LTM|(  
SFVqUg3"Z  
E$s?)  
public static void log(int sMsg) A<[BR*n  
{ 5XinZ~  
System.err.println(sMsg); >44,Dp]  
} 8WLBq-]G  
} @c;:D`\p1C  
R&MetQ~-{  
l *+9R  
/* Jv59zI  
**TestMethod.java zUz j F  
*/ %dq |)r  
package NetFox; *q0vp^?  
U2*kuP+n  
)CG,Udu  
public class TestMethod { oZw#]Q@  
>"pHk@AWK  
e{}vT$-  
public TestMethod() r%xf=};  
{ ///xx/weblogic60b2_win.exe #>O+!IH   
try{ >5j&Q#Bu  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f|&, SI?  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [*d<LAnuWP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); NkYC(;g  
fileFetch.start(); 2 t:CK  
} husk\  
catch(Exception e){e.printStackTrace ();} q82yh&  
o*:D/"gb  
b$=c(@]  
} -02.n}u>  
sQ8kLS_q8  
mC./,a[  
public static void main(String[] args) +/!y#&C&*  
{ }cERCS\t  
new TestMethod(); `0Xs!f  
} =4LyE6  
} [*^ rH:  
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:
3+5=?,请输入中文答案:八 正确答案:八