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
  • 9166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
/* }gd'pgN"t  
**SiteFileFetch.java r,P`$-  
*/ NT9|``^Z  
package NetFox; *thm)Mn  
import java.io.*; J.c yb  
import java.net.*; @Z<Z//^k  
| S'mF6Y  
vr_Z0]4`C9  
public class SiteFileFetch extends Thread { ?R4%z2rcW  
6<f(Zv? I  
,MG`} *N}  
SiteInfoBean siteInfoBean = null; //文件信息Bean *0<)PJ T  
long[] nStartPos; //开始位置 }?sC1]-j&  
long[] nEndPos; //结束位置 pB7^l|\]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 4Ofkagg  
long nFileLength; //文件长度 A-YW!BT4  
boolean bFirst = true; //是否第一次取文件 QI78/gT,d  
boolean bStop = false; //停止标志 ]3 QW\k~  
File tmpFile; //文件下载的临时信息 \=o0MR  
DataOutputStream output; //输出到文件的输出流 {*K$gH$  
#WAX&<m  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) a TPq1u  
public SiteFileFetch(SiteInfoBean bean) throws IOException v3<q_J'qT  
{ ^Ww5@  
siteInfoBean = bean; g1Osd7\o  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); s3 VD6xi7  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); buhbUmQ2  
if(tmpFile.exists ()) {P )O#  
{ 3 {|]@ L  
bFirst = false; #G=AD/z  
read_nPos(); eL{$=Um  
} DD`DU^o<  
else Gz(l~!n~a  
{ n+k,:O5  
nStartPos = new long[bean.getNSplitter()]; Z{?T1 =n  
nEndPos = new long[bean.getNSplitter()]; >=.3Vydi1  
} Rgl cd  
[.&n,.k  
Ei=rBi  
=J'Q%qN<Zd  
} Hlpt zez  
]0W64cuT  
%.HLO.A  
public void run() 5Sb-Bn  
{ ]ZNFrpq  
//获得文件长度 Q8$;##hzt  
//分割文件 {uJ"%  
//实例FileSplitterFetch SIc~cZ!Yu  
//启动FileSplitterFetch线程 _/Ay$l;F  
//等待子线程返回 `g0^ W/ j  
try{ ES8(:5  
if(bFirst) \r [@A3O  
{ 7OS i2  
nFileLength = getFileSize(); 08! _B\  
if(nFileLength == -1) 4&v&XLkb  
{ V/zmbo)  
System.err.println("File Length is not known!"); *p9k> )'J  
} N7YCg  
else if(nFileLength == -2) B![:fiR`  
{ {SD%{  
System.err.println("File is not access!"); [a?bv7Kz  
} A;o({9VH`Z  
else Ge^,hAM'  
{ ^66OzT8A  
for(int i=0;i<nStartPos.length;i++) =YD<q:n4  
{ ukRmjHbLf  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Mc$rsqDz  
} E[4 vUnm-  
for(int i=0;i<nEndPos.length-1;i++) *B9xL[}  
{ GK[9IF#_>  
nEndPos = nStartPos[i+1]; nq~fH(QY  
} ixE w!t  
nEndPos[nEndPos.length-1] = nFileLength; hTmJ ~m'J  
} 6\`8b&'n  
} 15yiDI o  
f.uy;v  
COmu.'%*  
//启动子线程 B+Ft  >  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Kf_xKW)^  
for(int i=0;i<nStartPos.length;i++) 7PBE(d%m  
{ \,r* -jr  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0j 8`M"6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), afzx?ekdF  
nStartPos,nEndPos,i); ?e,:x ]\L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #)]/wqPoW  
fileSplitterFetch.start(); mIqm/5  
} =E^/gc%X  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I5`>XfO)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wh~,?}laj  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lcgG5/82  
nEndPos = " + nFileLength); 8si{|*;hL  
// fileSplitterFetch[nPos.length-1].start(); VT=gb/W6)a  
PsD)]V9%:  
0rm(i*Q  
//等待子线程结束 o[i*i<jv-  
//int count = 0; 7AWq3i{  
//是否结束while循环 =6'bGC%c  
boolean breakWhile = false; P ?n k>  
gsl_aW!  
8Op^6rX4  
while(!bStop) jzBW'8  
{ _*b`;{3  
write_nPos(); jicH94#(]  
Utility.sleep(500); .GL@`7"  
breakWhile = true; S ?J(VJqE  
`"<hO 'WU  
lP*=4Jh  
for(int i=0;i<nStartPos.length;i++) `AvK=]  
{ G6G-qqXy6  
if(!fileSplitterFetch.bDownOver) ]qu6/Z  
{ 65*Hf3~~  
breakWhile = false; w{So(AF  
break; \sfc!5G  
} '>n&3`r5  
} hw*u.46  
if(breakWhile) [Q J  
break; zufsmY4P  
h.KgHMV`  
lNtxM"G&  
//count++; 1i_%1Oip  
//if(count>4) 3la`S$c  
// siteStop(); K<`W>2"  
} _Hfpizm  
5`gVziS!S  
j+{cc: h"X  
System.err.println("文件下载结束!"); 7YK6e  
} >]C/ Q6  
catch(Exception e){e.printStackTrace ();} mg@Ol"2  
} (@qS  
AE~@F4MK  
SJc~E$5<  
//获得文件长度 !H{>c@i  
public long getFileSize() mH4u@aQ}  
{ `'k2gq&  
int nFileLength = -1; ~(huUW  
try{ >5"e<mwD7d  
URL url = new URL(siteInfoBean.getSSiteURL()); >goHQ30:  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (E&M[hH+  
httpConnection.setRequestProperty("User-Agent","NetFox"); ysl#Rwt/2  
s S#/JLDx]  
3}&3{kt  
int responseCode=httpConnection.getResponseCode(); DHx&%]r;D  
if(responseCode>=400) $!y^t$u$@  
{ J YA>Q&  
processErrorCode(responseCode); M_.Jmh<&&  
return -2; //-2 represent access is error (2M00J-o  
} ^cSfkBh  
}#%Y eCA?  
-!O8V  
String sHeader; z,7;+6*=L  
@:#J^CsM+'  
jm@M"b'{  
for(int i=1;;i++) D!/ 4u0m  
{ /h.{g0Xc  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xpo^\E?2  
//Utility.log(in.readLine()); #62ThH~  
sHeader=httpConnection.getHeaderFieldKey(i); hsS&|7Pt  
if(sHeader!=null) N:k>V4oE  
{ tcsb]/my  
if(sHeader.equals("Content-Length")) gsM^Pu09ud  
{ |G$-5 7fk  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dq$1 j%4Y  
break; Y~A I2HS  
} }1~9i'o%Z  
} #N >66!/V  
else "::2]3e  
break; 6NhGTLI  
} %dq%+yw{%m  
} F;h^o!W7r  
catch(IOException e){e.printStackTrace ();} B)1(  
catch(Exception e){e.printStackTrace ();} K[0z$T\  
D15-pz|Q  
u a_w5o7  
Utility.log(nFileLength); v1X[/\;U  
T4"D&~3 3q  
ztX$kX:_m  
return nFileLength; ;v2eAe@7  
} /F~/&p1<\k  
x9a\~XL>a  
i20y\V os?  
//保存下载信息(文件指针位置) knph549  
private void write_nPos() K%mR=u#%&  
{ SJMbYjn0J  
try{ HiU)q  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~9vK 6;0  
output.writeInt(nStartPos.length); ujmIS~"  
for(int i=0;i<nStartPos.length;i++) j|K;Yi  
{ qm:C1#<p   
// output.writeLong(nPos); ~D4l64  
output.writeLong(fileSplitterFetch.nStartPos); j 4=iHnE;  
output.writeLong(fileSplitterFetch.nEndPos); eI2HTFyT  
} eA-oqolY  
output.close(); $,U/,XA {E  
} ,*d8T7T  
catch(IOException e){e.printStackTrace ();} SlR//h  
catch(Exception e){e.printStackTrace ();} ZAN~TG<n  
} >(.|oT\Tb  
=#y;J(>~|  
PQSmBTs.  
//读取保存的下载信息(文件指针位置) KA?%1s(kJ  
private void read_nPos() sCrP+K0D  
{ OW\vbWX  
try{ 87+fd_G  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =mZYBm,IQ  
int nCount = input.readInt(); Y:,C_^$w;  
nStartPos = new long[nCount]; #Pf<2S  
nEndPos = new long[nCount]; <4vCx  
for(int i=0;i<nStartPos.length;i++) jK*d  
{ ~S;-sxoO0l  
nStartPos = input.readLong(); Q>Z~={"  
nEndPos = input.readLong(); g H'hA'  
} jI*@&3  
input.close(); wS#Uw_[  
} 6fo" k+S  
catch(IOException e){e.printStackTrace ();} w(S~}'Sg*P  
catch(Exception e){e.printStackTrace ();} NQ 6oyg@&  
} 1v`|mU}i,  
E7? n'!=  
5=|h~/.k  
private void processErrorCode(int nErrorCode) 7I"~a<f0X`  
{ 5o>`7(t`  
System.err.println("Error Code : " + nErrorCode); rM A%By^L-  
} [w@S/K[_|  
GU2TQx{V  
MQN~I^v3  
//停止文件下载 |/n7(!7$[v  
public void siteStop() ^tG,H@95  
{ \X %FM"r  
bStop = true; ``VE<:2+  
for(int i=0;i<nStartPos.length;i++) i.)n#@M2  
fileSplitterFetch.splitterStop(); t^YtP3`?b  
jmaw-Rx  
Jk&!(YK&  
} pY )x&uM!  
} SF,:jpt`Z+  
//负责部分文件的抓取 X5[t6q!  
**FileSplitterFetch.java {x,)OgK!{  
*/ ?yq=c  
package NetFox; Um4zI>  
x} c  
.-tR <{ g  
import java.io.*; 2xO[ ?fR  
import java.net.*; DH+kp$,}  
zs I?X>4  
(ub(0 h0j  
public class FileSplitterFetch extends Thread { Il&7n_ H  
dG5jhkPX  
SF-"3M  
String sURL; //File URL cRrJZ9  
long nStartPos; //File Snippet Start Position M3@qhEf?vk  
long nEndPos; //File Snippet End Position s<!G2~T  
int nThreadID; //Thread's ID DAWF =p]  
boolean bDownOver = false; //Downing is over /Z^a, %1  
boolean bStop = false; //Stop identical L@AFt)U  
FileAccessI fileAccessI = null; //File Access interface J.4U;A5  
]9/A=p?J@  
}l$zZ>.\H  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r.#r!.6 q  
{ r1%{\<   
this.sURL = sURL; %?gG-R  
this.nStartPos = nStart; a"U3h[;$y  
this.nEndPos = nEnd; -sJD:G,%  
nThreadID = id; q&v~9~^}d  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !10/M  
} rmkBp_i{|  
K\U`gTGc  
v8yCf7+"  
public void run() {*GBUv5  
{ v(.mM9>  
while(nStartPos < nEndPos && !bStop) BX[ IWP\%  
{ PL$XXj>|:  
8HBwcXYoHh  
I P#vfM  
try{ {q8|/{;  
URL url = new URL(sURL); )?#K0o[<  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @hg[v`~  
httpConnection.setRequestProperty("User-Agent","NetFox"); N^[ F+y  
String sProperty = "bytes="+nStartPos+"-"; aQx6;PC  
httpConnection.setRequestProperty("RANGE",sProperty); /Ls|'2J<$  
Utility.log(sProperty); zu @|"f^`  
zMP6hn  
W1"NKg~4  
InputStream input = httpConnection.getInputStream(); ff.k1%wr^  
//logResponseHead(httpConnection); CS~onf<xz  
=Vs?=|r  
n8;L_43U  
byte[] b = new byte[1024]; xk>cdgt  
int nRead; dR\yRC]I  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }a5TY("d9H  
{ 3R%JmLM+R9  
nStartPos += fileAccessI.write(b,0,nRead); gtMR/P:S  
//if(nThreadID == 1) Fik ;hB  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |wuTw|  
} A)n_ST0  
LZ_VLW9w E  
,S`n?.&& 7  
Utility.log("Thread " + nThreadID + " is over!"); 5O]tkHYR  
bDownOver = true; U~ a\v8l~  
//nPos = fileAccessI.write (b,0,nRead); unn2I|XH  
} 8ly)G  
catch(Exception e){e.printStackTrace ();} K(u pz n*a  
} us|Hb  
} 1DcBF@3sWG  
>^g2 Tg:  
QEt"T7a[/  
//打印回应的头信息 (jU_lsG  
public void logResponseHead(HttpURLConnection con) >>KI_$V  
{ )GG9[%H!  
for(int i=1;;i++) xgIb6<qwY  
{ aIa<,  
String header=con.getHeaderFieldKey(i); '1 2*'Q+{+  
if(header!=null) RDDA^U7y#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uNuFD|aQ.  
Utility.log(header+" : "+con.getHeaderField(header)); T=-UcF  
else +fboTsp% H  
break; M}11 tUl  
} |A*4Fuc&  
} 7=?!B#hm !  
G5U?]& I8  
Ar >JQ@0  
public void splitterStop() %zGv+H?  
{ ~Oq _lM  
bStop = true; y$-@|M$GG  
} ? eX$Wc{  
AeEdqX)  
\)uA:v  
} 2=K|kp5  
B6IKD  
-n|>U:  
/* c$ib-  
**FileAccess.java o[Qb/ 7  
*//文件访问(定位,写) GP4!t~"1  
package NetFox; 4bL *7bA  
import java.io.*; S"G(_%  
uQ_C<ii"W  
%b*N.v1+  
public class FileAccessI implements Serializable{ M-h+'G  
LRu*%3xx  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yKj}l,i~8  
RandomAccessFile oSavedFile; +zche  
long nPos; 1K/ :  
1HNP@9ga  
F!hjtIkPj  
public FileAccessI() throws IOException #3_g8ni5X  
{ 6:%lxG  
this("",0); )ddJ\:  
} R$l- 7YSt  
bFN/{^SB  
!YGHJwW:  
public FileAccessI(String sName,long nPos) throws IOException N5zWeFq@6  
{ up['<Kt+a  
oSavedFile = new RandomAccessFile(sName,"rw"); L$O\fhO?  
this.nPos = nPos; ^ICSh8C  
oSavedFile.seek(nPos); ?+ d{Rh) y  
} G.L}VpopM  
/# Jvt  
ldp9+7n~  
public synchronized int write(byte[] b,int nStart,int nLen) y[l{ UBue:  
{ I>nYI|o1  
int n = -1; Ek `bPQ5  
try{  .GJbrz  
oSavedFile.write(b,nStart,nLen); ly34aD/p~,  
n = nLen; q 6UZ`9&z  
} lbt8S.fx  
catch(IOException e) D1-w>Y#  
{ pm=O.)g4`  
e.printStackTrace (); Ag\RLJ.KD  
} RjviHd#DXn  
oh$"?N7n1  
:^`j:B  
return n; n6Uh%rO7S|  
}  N{g7  
,m`&J?  
\i,H1a  
} GFPrK9T  
q['D?)sy  
~cp=B>*(  
/* *LBF+L^C%  
**SiteInfoBean.java nkPlfH  
*/ \9p.I?=  
package NetFox; [I%e Ro[  
Jxe5y3* (  
S[9b I&C  
public class SiteInfoBean { 2"a%%fv  
^kcuRJ0*$  
8i;drvf  
private String sSiteURL; //Site's URL {ST8'hY  
private String sFilePath; //Saved File's Path ec#`9w$  
private String sFileName; //Saved File's Name J&h59dm-  
private int nSplitter; //Count of Splited Downloading File :9 (kU  
5s^vC2$)  
9+m>|"F0  
public SiteInfoBean() |7,$.MK-@  
{//nSplitter的缺省值为5 uZ_?x~V/  
//default value of nSplitter is 5 H74'I}  
this("","","",5); }03?eWk/y  
} <!G /&T  
sdCG}..`  
V}<<?_  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fFbJE]jW  
{ P]}:E+E<.I  
sSiteURL= sURL; 11QZ- ^  
sFilePath = sPath; S9l po_!z  
sFileName = sName; {}'Jr1  
this.nSplitter = nSpiltter; YY tVp_)  
r%=a:GdAg  
AFsieJ  
} 6@# =z  
.yUD\ZGJ u  
Gl{'a1  
public String getSSiteURL() 7\$}|b[9  
{ /o$6"~t  
return sSiteURL; g$)0E<  
} Tg@G-6u0c  
34)l3UI~  
7`L]aRS[  
public void setSSiteURL(String value) 0hkYexX73  
{ ) xV>Va8)  
sSiteURL = value; 9fbo  
} n@kJ1ee'  
h){#dU+&  
@/As|)  
public String getSFilePath() D.7cWR`Wp  
{ B(71I;  
return sFilePath; EqD@o  
} "S{GjOlEDF  
8TH;6-RT  
dQH8s  
public void setSFilePath(String value) {7IZN< e  
{ {be|G^.c  
sFilePath = value; A`vRUl,c=  
} :SN?t  
OBlQ   
$M-"az]  
public String getSFileName() rFC9y o  
{ v%`k*n':  
return sFileName; 4s>L]! W$8  
} *}HDq(/>w  
j1Sjw6}GCH  
w"M!**bP  
public void setSFileName(String value) 4M>]0%3.D  
{ #>CWee;  
sFileName = value; rjfWty%6pX  
} >PdrLwKS  
pkG8g5(w  
)<'2 vpz  
public int getNSplitter() 2^5RQl/  
{ 33}p02#  
return nSplitter; qixnaiZ  
} _ !"[Zr  
buKkm$@w  
A;/,</  
public void setNSplitter(int nCount) H,/ =<Th;i  
{ `7`` 1TL  
nSplitter = nCount; _q-k1$ o$  
} 4yMi9Ri4H  
} 5``usn/&Kj  
5K|`RzZ`B$  
5D^2 +`$/  
/* d"ZsOq10D  
**Utility.java ,HE{&p2y  
*/ 0Iyb}  
package NetFox; '|tmmoY6a:  
Frx_aGLH1  
8&x&Ou$("V  
public class Utility { /^~)iTwH  
y(C',Xn  
44^jE{,9  
public Utility() ] :](xW%  
{ qw|B-lT{:  
~:0U.v_V  
*&_(kq z'1  
} |U~\;m@  
&u2m6 r>W  
//线程睡眠 GIkVU6Q}  
public static void sleep(int nSecond) '|%\QWuZ  
{ u8x#XESR7  
try{ yi-)4#YN  
Thread.sleep(nSecond); "[_gRe*2  
} l~1l~Gx_&n  
catch(Exception e) =jG."o  
{ )ZZ6 (O  
e.printStackTrace (); \<} e?Yx%  
} gZz5P>^  
} mX @xV*  
*L<<S=g$2  
//日志 FYg{IKg  
public static void log(String sMsg) /I`-  
{ k1D|Cpnp  
System.err.println(sMsg); VB+_ kR6Zv  
} ?%>S5,f_  
8js1m55KT  
R C!~eJG!  
public static void log(int sMsg) ]>+ teG:4  
{ o8A(Cg}  
System.err.println(sMsg); xiC.M6/  
} u3 4.   
} i Hcy,PBD  
5cr\ JR  
1R.6Xer  
/* @zsqjm  
**TestMethod.java _^0UK|[  
*/ y&F&Z3t  
package NetFox; PC?XE8o  
*M~BN}.  
;T!ZO@1X  
public class TestMethod { Z7MGBwP(  
sdQ "[`~2R  
*APTgXYR  
public TestMethod() SQG9m2  
{ ///xx/weblogic60b2_win.exe qHYoQ.ke  
try{ oHethk  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ) @f6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ir;az{T#U  
SiteFileFetch fileFetch = new SiteFileFetch(bean); s<LYSrd  
fileFetch.start();  (=Lx9-u  
} 40;4=  
catch(Exception e){e.printStackTrace ();} FCt %of#  
EHq?yj;  
>\1j`/ :ZI  
} [@$t35t~  
U ,\t2z  
$)j f  
public static void main(String[] args) cD<5~`l  
{ Xf|I=XK  
new TestMethod(); _$gP-J  
} S1*xM  
} @$|bMH*1:  
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