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
  • 7513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
/* $ w:QJ~,s  
**SiteFileFetch.java +Vt@~Z4K  
*/ O*rKV2\  
package NetFox; rPkV=9ull,  
import java.io.*; BgJ;\NV  
import java.net.*; /A[AHJ<[?  
y _>HQs,:  
AnG/A!G  
public class SiteFileFetch extends Thread { _sbZyL  
~<Uwum v  
V' "p a  
SiteInfoBean siteInfoBean = null; //文件信息Bean o;M"C[  
long[] nStartPos; //开始位置 8},!t\j#]  
long[] nEndPos; //结束位置 SC74r?N FA  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 8b !&TP~m1  
long nFileLength; //文件长度 !0 `44Gbq  
boolean bFirst = true; //是否第一次取文件 'CjcOI s  
boolean bStop = false; //停止标志 ='T<jV`evu  
File tmpFile; //文件下载的临时信息 bw9a@X  
DataOutputStream output; //输出到文件的输出流 2!cP[ Ck  
i;y<gm"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }&d]Uv/4  
public SiteFileFetch(SiteInfoBean bean) throws IOException nBjfR2TuF  
{ ueZ`+g~gg  
siteInfoBean = bean; 5[]7baO)h1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); zv||&Hi  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); .Gh-T{\V'  
if(tmpFile.exists ()) thOQcOf0$  
{ 0XSZ3dY&+  
bFirst = false; >&RpfE[  
read_nPos(); ko@I]gi2  
} Nj*J~&6G  
else U: ~O^  
{ !FZb3U@  
nStartPos = new long[bean.getNSplitter()]; 5@P2Z]Q  
nEndPos = new long[bean.getNSplitter()]; \;I%>yOIu  
} >e($T!}Z  
:g}WN  
Ti#2D3  
,E$^i~OO  
} 4&!`Yi_1L  
*J=`"^BO  
? Sj,HLo@U  
public void run() )}9Ef"v|  
{ ' ]l,  
//获得文件长度 YDyOhv  
//分割文件 |s+[489g'6  
//实例FileSplitterFetch 8k2prv^  
//启动FileSplitterFetch线程 0SwWLq  
//等待子线程返回 FcdbL,}=<  
try{ 'D-eFJ5  
if(bFirst) M['8zN  
{ `]#DdJ_|  
nFileLength = getFileSize(); (WCpaC  
if(nFileLength == -1) .8uJ%'$)  
{ qS*qHT(u19  
System.err.println("File Length is not known!"); 9(QY~F  
} W=&\d`><k  
else if(nFileLength == -2) HtgVD~[]  
{ 8TD:~ee  
System.err.println("File is not access!"); P7&a~N$T6W  
} `8\ _ ]w0  
else /P<RYA~  
{ ]$Ky ZHj{  
for(int i=0;i<nStartPos.length;i++) D\ HmY_  
{ A?ma5h  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); DhG2!'N  
} U2$e?1y  
for(int i=0;i<nEndPos.length-1;i++) j0>S)Q  
{ 3P\#moJ  
nEndPos = nStartPos[i+1]; p )etl5  
} `][~0\Y3m  
nEndPos[nEndPos.length-1] = nFileLength; 6vQAeuz<Fq  
} cT`x,2  
} (zwxrOS  
O`g44LW2n  
i{I'+%~R  
//启动子线程 Xnt`7L<L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zq80}5%2CT  
for(int i=0;i<nStartPos.length;i++) 8RVNRV@g%  
{ T12?'JL^r  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &q#$SU,$(  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f7)}A/$4+  
nStartPos,nEndPos,i); D06'"  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?=dyU(  
fileSplitterFetch.start(); mLd=+&M  
} k`62&"T  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;gc Q9L  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yyPkjUy[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MlkTrKdGi  
nEndPos = " + nFileLength); AA;\7;k{  
// fileSplitterFetch[nPos.length-1].start(); 1 9$ufod  
puG$\D-[  
u3R0_8 _.w  
//等待子线程结束 "pa5+N&2-  
//int count = 0; Vz1ro  
//是否结束while循环 lj/ ?P9  
boolean breakWhile = false; sOa`Tk  
#[ vmS  
r50}j  
while(!bStop) HTao)`.  
{ @ eqVu g  
write_nPos(); Qf6]qJa|  
Utility.sleep(500); ,}2M'DSWa  
breakWhile = true; x|<rt96 6A  
>:4}OylhM  
tQ< ou,   
for(int i=0;i<nStartPos.length;i++) =SA@3)kHH  
{ IVzJ|  
if(!fileSplitterFetch.bDownOver) pFX Do4eH  
{ 9w[7X"#n  
breakWhile = false; 68V66:0  
break; [h""AJ~t  
} vRp =L54z  
} A-aukJg9  
if(breakWhile) /k|y\'<  
break; IFlDw}M!9  
3o9`Ko0  
%L.,:mtq)  
//count++; )?^0<l#s  
//if(count>4) (Gf1#,/3~  
// siteStop(); cF_ Y}C  
} PaP47>(  
\|BtgT*$b  
'b]GcAL  
System.err.println("文件下载结束!"); '*MNRduE6  
}  ]hpocr  
catch(Exception e){e.printStackTrace ();} tu#VZAPW@  
} ),v[.9!}:  
+v2Fr}  
dy-m9fc6%  
//获得文件长度 &, hhH_W  
public long getFileSize() 5&D)W>{d  
{ (s4w0z  
int nFileLength = -1; }BlVLf%C  
try{ u7ZSs-LuHw  
URL url = new URL(siteInfoBean.getSSiteURL()); wo5"f}vd#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oJK1~;:  
httpConnection.setRequestProperty("User-Agent","NetFox"); v3x_8n$C9  
/@g D 8  
|G&<@8O  
int responseCode=httpConnection.getResponseCode(); ^8Tq0>n?  
if(responseCode>=400) lO3$V JI  
{ ZE.nB- H  
processErrorCode(responseCode); xbnx*4o0  
return -2; //-2 represent access is error h-+9Bv]  
} 5"%r,GMU  
I7ZY9W(S  
}`E5I&r4  
String sHeader; Rx<m+=  
2Vas`/~u~  
`*mctjSN  
for(int i=1;;i++) IeLG/ fB  
{ R$X1Q/#md  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }dX[u`zQ  
//Utility.log(in.readLine()); N`1:U 4}  
sHeader=httpConnection.getHeaderFieldKey(i); 2>p K  
if(sHeader!=null) %W~Kx_  
{ L}UJ`U  
if(sHeader.equals("Content-Length")) vQ>x5\r5O_  
{ 0+jR,5 |  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X|^E+ `M4  
break; G7yCGT)vQ  
} lyNa(3  
} Eo 5p-  
else f=]+\0MQ  
break; Gl}[1<~o  
} Ox7v*[x'  
} #|k;nFJ  
catch(IOException e){e.printStackTrace ();} qL.1N~$2  
catch(Exception e){e.printStackTrace ();} x9k(mn%,  
_p<W  
FivgOa  
Utility.log(nFileLength); `9E:V=  
@GDe{GG+  
h[b5"Uqj  
return nFileLength; @]P#]%^D2  
} 9\ZlRYnc=  
Y f:xM>.%  
%K8Ei/p\t]  
//保存下载信息(文件指针位置) DXu#07\  
private void write_nPos() {R%v4#nk  
{ _ +[;NBz  
try{ dP63bV  
output = new DataOutputStream(new FileOutputStream(tmpFile)); uCO-f<b  
output.writeInt(nStartPos.length); <aR9,:  
for(int i=0;i<nStartPos.length;i++) u>o<u a p  
{ c,pR+DP  
// output.writeLong(nPos); <^q4^Q[  
output.writeLong(fileSplitterFetch.nStartPos); 2 eo]D?}  
output.writeLong(fileSplitterFetch.nEndPos); LsH&`G^<  
} A]L;LkEM  
output.close(); }tA77Cm)45  
} j hf%ze  
catch(IOException e){e.printStackTrace ();} 1;?n]L`T  
catch(Exception e){e.printStackTrace ();} JX8Hn |  
} Q xZYy}2  
<9z2:^  
(8qD'(@  
//读取保存的下载信息(文件指针位置) X`xmV!  
private void read_nPos() C"}CD{<H]M  
{ KU#w %  
try{ DjY&)oce(  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -x)Oo`  
int nCount = input.readInt(); AdBB#zd  
nStartPos = new long[nCount]; 12qX[39/  
nEndPos = new long[nCount]; lx _jy>$}r  
for(int i=0;i<nStartPos.length;i++) s\2t|d   
{ VM=A#}  
nStartPos = input.readLong(); eH,r%r,  
nEndPos = input.readLong(); {JTO Q 8&  
} TbX#K:l  
input.close(); &x6Z=|Ers  
} E0; }e  
catch(IOException e){e.printStackTrace ();} ~R^~?Y%+<  
catch(Exception e){e.printStackTrace ();} tmT/4Ia  
} Pu/X_D-#Gi  
HwfBbWHr'  
\) DJo  
private void processErrorCode(int nErrorCode) )7!q>^S{ B  
{ VqGmZ|+8  
System.err.println("Error Code : " + nErrorCode); Ey<vvZ  
} 8CCd6)cG  
]."~)  
qd$Y"~Mco  
//停止文件下载 [Q+8Ku  
public void siteStop() F]o&m::/K  
{ SNqw 2f5  
bStop = true; [ u7p:?WDW  
for(int i=0;i<nStartPos.length;i++) F/,K8<|r>  
fileSplitterFetch.splitterStop(); 4)MKYhm  
xPMTmx?2  
v0uDL7  
} Mh [TZfV  
} IIrh|>d_7  
//负责部分文件的抓取 lh^-L+G:Ok  
**FileSplitterFetch.java L3}n(K AJj  
*/ Su.imM!  
package NetFox; N3/G6wn  
Mbbgsy3W  
`! ~~Wf'  
import java.io.*; ;#-yyU  
import java.net.*;  dxHKXw  
#9{N[t  
(=#[om( A  
public class FileSplitterFetch extends Thread { |NuX9!S  
C>l{_J)n  
' cM2]<  
String sURL; //File URL me-Tv7WL  
long nStartPos; //File Snippet Start Position 1^&qlnqH  
long nEndPos; //File Snippet End Position A"|y<  
int nThreadID; //Thread's ID @c 3GJ'"X  
boolean bDownOver = false; //Downing is over {2jetX`@h  
boolean bStop = false; //Stop identical {Yq"%n'0  
FileAccessI fileAccessI = null; //File Access interface EJC{!06L'/  
c%|K x  
i,#j@R@.C7  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2XoFmV),F  
{ `y"(\1  
this.sURL = sURL; W)F<<B,  
this.nStartPos = nStart; JF{yhx,+ p  
this.nEndPos = nEnd; abog\0  
nThreadID = id; XS:W{tL!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tx+!D'>  
} "rxhS; R1>  
7oUecyoj  
^n! j"  
public void run() (41BUX  
{ GD*rTtDWn  
while(nStartPos < nEndPos && !bStop) poLzgd  
{ 9Q\CJ9  
( X(61[Lu  
5:S=gARz  
try{ >i&"{GZ  
URL url = new URL(sURL); 73/DOF  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `Wc"Ix0  
httpConnection.setRequestProperty("User-Agent","NetFox"); VycC uq&M  
String sProperty = "bytes="+nStartPos+"-"; etnq{tE5  
httpConnection.setRequestProperty("RANGE",sProperty); )y~FeKh  
Utility.log(sProperty); %@C(H%obWd  
V2Iq k]V%y  
++>HU{  
InputStream input = httpConnection.getInputStream(); <jt_<p +  
//logResponseHead(httpConnection); KMs[/|HX\  
d,%e? 8x5  
^a>3U l{  
byte[] b = new byte[1024]; eXs^YPi  
int nRead; _:N+mEF  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T"h@-UcTl  
{ pr~%%fCh  
nStartPos += fileAccessI.write(b,0,nRead); 1co;U  
//if(nThreadID == 1) R7'6#2y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a7$]" T 7  
} ojmF:hR"  
'gBGZ?^N!U  
XK*55W &og  
Utility.log("Thread " + nThreadID + " is over!"); dUt$kB  
bDownOver = true; =w&bS,a"y  
//nPos = fileAccessI.write (b,0,nRead); RSv?imi=  
} 4lM)ZDg  
catch(Exception e){e.printStackTrace ();} <@F.qMl  
} 5OJ8o>BF  
} B=ckRW q  
hB?a{#JL  
aNt+;M7g`  
//打印回应的头信息 4*`AYx(  
public void logResponseHead(HttpURLConnection con) cj[a^ ZH  
{ EN,PI~~F  
for(int i=1;;i++) !O*'mX  
{ iX&eQ{LB  
String header=con.getHeaderFieldKey(i); g4eEkG`XTS  
if(header!=null) X  jPPgI  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); st_.~m!/  
Utility.log(header+" : "+con.getHeaderField(header)); \*a7o GyH>  
else ,(&p "O":  
break; >Bw<THx  
} Tasmbo^mAF  
} 95XQ?%  
w}20l F  
9#;GG3  
public void splitterStop() ?&gqGU}  
{ +6zW(Ql/  
bStop = true; Pv#Oea?  
} "=0(a)01p:  
?IN'Dc9&%-  
24g\x Nnt  
} $a@T:zfe  
&b__ /o  
nE&`~  
/* i]cD{hv  
**FileAccess.java 9mmkFaBQ  
*//文件访问(定位,写) ^ gMkQYo(#  
package NetFox; WX-J4ieL  
import java.io.*; f]_{4Olk  
5n0B`A  
icrcP ~$A  
public class FileAccessI implements Serializable{ MQ#nP_i  
H1t`fyri2  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xS'Kr.S  
RandomAccessFile oSavedFile; jW8,}Xs  
long nPos; ?lPn{oB9"  
**G5fS.^W  
k#g` n3L  
public FileAccessI() throws IOException f,}(= u  
{ a23XrX  
this("",0); hl/) 1sOIR  
} FHK{cE  
A3 uF 0A  
4@mK:v %  
public FileAccessI(String sName,long nPos) throws IOException i^SPNs=  
{ FUO9jX  
oSavedFile = new RandomAccessFile(sName,"rw"); w-j^jU><3  
this.nPos = nPos; L-9 AJk>V  
oSavedFile.seek(nPos); C>:,\=y%  
} tH)fu%:p  
J+(B]8aj  
Pf:;iXH?  
public synchronized int write(byte[] b,int nStart,int nLen) 5r` x\  
{ 6uTFgSqZ  
int n = -1; Bjp4:;Bb  
try{ `DFo:w!k  
oSavedFile.write(b,nStart,nLen); A"}Ib'  
n = nLen; &}rmDx  
} 5$?)f&M  
catch(IOException e) rJM/.;Ag  
{ b|DiU}  
e.printStackTrace (); e~ZxDAd  
} t?(fDWd|-  
"?M)2,:A  
)Tl]1^  
return n; |V&E q>G  
} ] :SbvsPm  
8yC/:_ML  
hDf!l$e.  
} 47=YP0r?>T  
Qx_]oz]NY  
ujf]@L?  
/* 8Q(A1U  
**SiteInfoBean.java so>jz@!EE  
*/ ]@6L,+W"  
package NetFox; 98rO]rg  
.Cu0G1  
 u*m|o8  
public class SiteInfoBean { d6XdN  
Y'+mC  
;U&~tpd  
private String sSiteURL; //Site's URL B; ^1W{%J  
private String sFilePath; //Saved File's Path vNQ|tmn  
private String sFileName; //Saved File's Name b:Tv Ta  
private int nSplitter; //Count of Splited Downloading File iOB*K)U1  
dAr=X4LE  
{ V$}qa{P  
public SiteInfoBean() H1d2WNr[  
{//nSplitter的缺省值为5 [85b+SKW  
//default value of nSplitter is 5 C({r1l4[D  
this("","","",5); lyzM?lK-  
} .3CQFbHF  
(5l'?7  
2@Zw#2|]  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9yK\<6}}QH  
{ 7P:/ (P  
sSiteURL= sURL; NpH:5hi  
sFilePath = sPath; hiEosI C  
sFileName = sName; 5p>rQq0  
this.nSplitter = nSpiltter; ^8=e8O  
*pYawT  
i3vg7V.  
} ~^J9v+  
HBm(l@#.  
jG%J.u^k  
public String getSSiteURL() ()ww9L2  
{ T}jW,Ost  
return sSiteURL; MP p    
} |)OC1=As  
#!C|~=  
5^N y6t  
public void setSSiteURL(String value) n(9$)B_y  
{ ~cf)wrP  
sSiteURL = value; K?u:-QX^  
} >?jmeD3u  
D^S"6v" z  
(@NW2  
public String getSFilePath() t9r R>Y9  
{ `-g$ 0lm7  
return sFilePath; XPLm`Q|1#t  
} qu0 q LM  
^ f[^.k$3d  
/jSb ^1\  
public void setSFilePath(String value) ~m4 LL[  
{ *rVI[k L  
sFilePath = value; {S`Rr/E|%  
} 5`QfysR5  
kyf(V)APPu  
oQR?H  
public String getSFileName() t!59upbN}3  
{ rAk;8)O$  
return sFileName; Rl'xEtaN  
} O&Y22mu  
gZ us}U  
ir5eR}H  
public void setSFileName(String value) l-2lb&n  
{ #!>`$  
sFileName = value; & j*Ylj}  
} 65GC7 >[  
:BF WX  
OI:T#uk5  
public int getNSplitter() [$M l;K  
{ 9t7 e~&R  
return nSplitter; nv3TxG  
} !iAZEOkRR  
<bJ~Ol  
]UrlFiR  
public void setNSplitter(int nCount) GS*_m4.Ry6  
{ G+WCE*  
nSplitter = nCount; [OFT!=.y &  
} t&-c?&FO\;  
} fO83 7  
D=)qd@,K  
9y*(SDF  
/* +A%zFF3  
**Utility.java *7qa]i^]  
*/ )O\l3h"  
package NetFox; + B7UGI  
JEfhr  
_+gpdQq\p  
public class Utility { ZJQkZ_9@2  
crJNTEz  
:(I=z6  
public Utility() NJKk\RM@7  
{ y*8;T v|  
eTt{wn;6  
5;[0Q  
} Xm6M s<z6  
R=W$3Ue~,  
//线程睡眠 w$749jGx  
public static void sleep(int nSecond) _X)]/A%@  
{ -./ Y  
try{ xG(:O@  
Thread.sleep(nSecond); z]sQ3"cmX  
} tAb3ejCo?  
catch(Exception e) O>ZJOKe  
{ &< hk&B  
e.printStackTrace (); !)c0  
} |\]pTA$2  
} `U;V-  
i k0w\*  
//日志 ^1ks`1  
public static void log(String sMsg) 6,]2;'  
{ mW)"~sA  
System.err.println(sMsg); C |rl",&  
} w$Mb+b$  
[{J1b  
os(}X(   
public static void log(int sMsg) / `w'X/'VJ  
{ -Q!?=JNtQ  
System.err.println(sMsg); ezd@>(hJ  
} Kw>gg  
} 4;w# mzd  
_xdttO^N  
;~s@_}&  
/* dRTpGz  
**TestMethod.java H/ub=,Ej*  
*/ cH7D@p}  
package NetFox;  ^9kdd[  
J1Y3>40  
NO#^_N`#\  
public class TestMethod { ,0$b8lb;x/  
q5w)i  
<7X+-%yb;  
public TestMethod() Rh7=,=u  
{ ///xx/weblogic60b2_win.exe t aOsC! Bp  
try{ y] ~X{v  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8\Eq(o}7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7M9s}b%?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3*b!]^d:D  
fileFetch.start(); &S# bLE  
} ~ K|o@LK  
catch(Exception e){e.printStackTrace ();} }Z\+Qc<<  
QLTE`t5w3'  
ZP%Bu2xd  
} NO)vk+   
fGLOXbsA  
.{ ]=v  
public static void main(String[] args) [g*]u3s  
{ u"a$/  
new TestMethod(); *$>$O%   
} s[@@INU  
} Iyvl6  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八