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
  • 9259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
/* ex6R=97uA  
**SiteFileFetch.java Hf\sF(, (  
*/ kguZAO6  
package NetFox; +@~WKa  
import java.io.*; aU^6FI  
import java.net.*; |<5F08]v  
U7 ?v4O]D[  
*mbzK*  
public class SiteFileFetch extends Thread { 8QZI(Xe9r  
O1S7t)ag  
CH&{x7$he  
SiteInfoBean siteInfoBean = null; //文件信息Bean ml<tH2Qx3C  
long[] nStartPos; //开始位置 -*z7`]5J  
long[] nEndPos; //结束位置 Jv+w{"&  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Fx|`0 LI+C  
long nFileLength; //文件长度 O^j*"#f  
boolean bFirst = true; //是否第一次取文件 &K{8- t  
boolean bStop = false; //停止标志 n\3#69VY  
File tmpFile; //文件下载的临时信息 J=t}9.H~=  
DataOutputStream output; //输出到文件的输出流 ;81,1 Ie<~  
q\~ #g.}  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) -z0;4O (K]  
public SiteFileFetch(SiteInfoBean bean) throws IOException iER@_?  
{  tH44\~  
siteInfoBean = bean;  ]%FAJ\  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); a4*976~![  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); f:ObI  
if(tmpFile.exists ()) /s} "0/Y\  
{ {(!JYz~P  
bFirst = false; 1P*hC<  
read_nPos(); kDMvTVd  
} HE%/+mZN  
else XUA@f*  
{ -1RMyVx  
nStartPos = new long[bean.getNSplitter()]; zh*D2/ r  
nEndPos = new long[bean.getNSplitter()]; FK593z  
} 5a$EXV  
[`t ;or  
V`1{*PrI@L  
U/^#nU.,  
} 7XK0vKmW3  
8hD[z}  
Cj<8r S4+  
public void run() tP7<WGHd/  
{ {MSE}|A\V  
//获得文件长度 4P k%+l  
//分割文件 ]i$0s  
//实例FileSplitterFetch t`+A;%=K]  
//启动FileSplitterFetch线程 6UuN-7z!"  
//等待子线程返回 t4[q :[1  
try{ HyVV,q^E  
if(bFirst) ]JYE#F  
{ ,>h"~X  
nFileLength = getFileSize(); BZ1wE1t  
if(nFileLength == -1) R`Z"ey@C  
{ nOvR, 6  
System.err.println("File Length is not known!"); .i I{  
} T+ZA"i+  
else if(nFileLength == -2) hdH z", )  
{ 1o%#kf  
System.err.println("File is not access!"); 45 sEhs[$  
} CqlxE/|  
else $R/@8qnP W  
{ _&BK4?H@b  
for(int i=0;i<nStartPos.length;i++) $Dj8 a\L  
{ YM:sLeQ~c  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); hm! J@  
} <1l%|   
for(int i=0;i<nEndPos.length-1;i++) jts0ZFHc-  
{ iX]OF.:   
nEndPos = nStartPos[i+1]; )>:~XA|?  
} A}(]J!rc  
nEndPos[nEndPos.length-1] = nFileLength; A-T-4I  
} _&hM6N  
} W~;Jsd=f  
u9OY Jo  
LSou]{R  
//启动子线程 RI&O@?+U  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P'lnS&yA  
for(int i=0;i<nStartPos.length;i++) FL^ _)`  
{ -&>V.hi7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9 A ?{}c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =wdh# {  
nStartPos,nEndPos,i); R+Hu?Dv&F  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U 5J _Y  
fileSplitterFetch.start(); LJ/He[r|[  
} gHBvQ1g  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1fS&KO{a  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KD &nLm!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1"ZtE\{ "  
nEndPos = " + nFileLength); +9b{Y^^~T  
// fileSplitterFetch[nPos.length-1].start(); KHML!f=mu  
>nghFm  
DJ,LQj  
//等待子线程结束 w~b:9_reY  
//int count = 0; ]u|v7}I4  
//是否结束while循环 n9+33^ PT  
boolean breakWhile = false; FtIcA"^N  
LUMbRrD-  
iAu/ t  
while(!bStop) [! $N Tt_  
{ Y7}Tuy dC  
write_nPos(); pY"WW0p"C  
Utility.sleep(500); &L+uu',M0c  
breakWhile = true; \Mg_Q$  
1n8[fgz  
e.n(NW  
for(int i=0;i<nStartPos.length;i++) z!"vez  
{ 3Tl<ST\  
if(!fileSplitterFetch.bDownOver) \9VF)Y.ke  
{ Q6qW?*Y  
breakWhile = false; (4+P7Z,Nc  
break; wsWFD xR  
} {=ox1+d  
} SV>tw`2  
if(breakWhile) =9jK\ T^  
break; A9MM^j V8  
<giBL L!  
10FiA;  
//count++; ^9[Q;=R  
//if(count>4) 13X}pnW  
// siteStop(); Food<(!.>  
} Y~I<Locv  
b"h'7C/  
Jbu2y'zE  
System.err.println("文件下载结束!"); $y8-JR~  
} 1D*=ZkA)  
catch(Exception e){e.printStackTrace ();} 1|MRXK  
} B}iEhWO6  
h 3CA,$HJ  
1hG#  
//获得文件长度 +-!E% $  
public long getFileSize() H$h#n~W~  
{ j<p.#jkT  
int nFileLength = -1; I%3[aBz4  
try{ U N9hZ>9  
URL url = new URL(siteInfoBean.getSSiteURL()); XIdh9)]^}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 32YbBGDN!f  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;o9h|LRs  
dht0PZdx?  
=u<:'\_  
int responseCode=httpConnection.getResponseCode(); 8<6H2~5<  
if(responseCode>=400)  [SPx  
{ MVYd\)\o  
processErrorCode(responseCode); DzAZv/h76  
return -2; //-2 represent access is error ;V}:0{p  
} {~U3|_"[pX  
yH/A9L,Z  
.e~"+Pe6b  
String sHeader; UT<e/  
5RP kAC  
.{V"Gn9!  
for(int i=1;;i++) $'J3 /C7  
{ 6zi>Q?] 1  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <CyU9`ye  
//Utility.log(in.readLine()); ]q]xU,  
sHeader=httpConnection.getHeaderFieldKey(i); hYW9a`Ht/  
if(sHeader!=null) }|DspO  
{ Oidf\%!mvR  
if(sHeader.equals("Content-Length")) Qm%PpQ^Lz3  
{ |bY@HpMp  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J usU5 e|  
break; EwP2,$;  
} Y sM*d  
} |b   
else ORExI.<`W  
break; }t H$:Z  
} r]3-}:vU  
} VXeO}>2S  
catch(IOException e){e.printStackTrace ();} EgjJywNhd2  
catch(Exception e){e.printStackTrace ();} F$7!j$ Z  
n>Ff tVZNJ  
U+Y(:  
Utility.log(nFileLength); $YSXE :  
8z9 {H  
#{cy(&cz  
return nFileLength; @aIgif+v  
} 5'zXCHt  
}Le]qR9Y]  
HlGSt$woX  
//保存下载信息(文件指针位置) +,76|oMsQ%  
private void write_nPos() `b?uQ\#-M  
{ 7UfNz60+~  
try{ ZVjB$-do  
output = new DataOutputStream(new FileOutputStream(tmpFile)); W XQ@kQD  
output.writeInt(nStartPos.length); 7~7L5PRW  
for(int i=0;i<nStartPos.length;i++) QN:v4,$d  
{ vF72#BNs  
// output.writeLong(nPos); w#"\*SKK  
output.writeLong(fileSplitterFetch.nStartPos); ^tB 1Nu %  
output.writeLong(fileSplitterFetch.nEndPos); "aJHCi~l  
} UL+Txc  
output.close(); 6D;N.wDZ  
} -%asHDQ{  
catch(IOException e){e.printStackTrace ();} p* >z:=  
catch(Exception e){e.printStackTrace ();} QaWS%0go  
} 1JJsYX  
w~66G  
$dL..QH^K  
//读取保存的下载信息(文件指针位置) #HUn~r  
private void read_nPos() p+d-7'?I  
{ x?h/e;  
try{ Kj4/fB  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o<G 9t6~  
int nCount = input.readInt(); qN!oN*  
nStartPos = new long[nCount]; \x<8   
nEndPos = new long[nCount]; g)X3:=['  
for(int i=0;i<nStartPos.length;i++) \[MAa:/  
{ .~]|gg~  
nStartPos = input.readLong(); ]eL# bJ  
nEndPos = input.readLong(); fUT[tkb/!  
} ?UXF z'  
input.close(); dOhSqx56  
} +,Eam6g{  
catch(IOException e){e.printStackTrace ();} 3lP;=* m.  
catch(Exception e){e.printStackTrace ();} 'a~@q~!  
} feej'l }F  
2dn^K3  
\nl(tU#j  
private void processErrorCode(int nErrorCode) SI7rTJ]/  
{ 3c<aI =$^  
System.err.println("Error Code : " + nErrorCode); 78& |^sq  
} "5hk%T '  
Xaq;d'  
hkMeUxS  
//停止文件下载 l]*RiK2AC  
public void siteStop() 7)Toj  
{ r4yz{^G  
bStop = true; eM7@!CdA9q  
for(int i=0;i<nStartPos.length;i++) f|d~=\0y  
fileSplitterFetch.splitterStop(); W`>|OiuF  
;:;E|{e  
aKI"<%PNn  
} y=3 dGOFB  
} 1/DtF  
//负责部分文件的抓取 j\y;~ V  
**FileSplitterFetch.java wi2`5G6|z  
*/ ^z?b6kTC  
package NetFox; (v]%kXy/G  
3?93Pj3oPt  
bZu'5+(@  
import java.io.*; R"nB4R0Uh  
import java.net.*; G%W9?4_K  
RY-iFydPc  
bC{4a_B  
public class FileSplitterFetch extends Thread { WtM%(8Y[]  
iq&3S0  
ipSMmpB  
String sURL; //File URL wuqe{?  
long nStartPos; //File Snippet Start Position (NJ{>@&  
long nEndPos; //File Snippet End Position 2#wnJdr6E  
int nThreadID; //Thread's ID bWe2z~dP  
boolean bDownOver = false; //Downing is over ;UdM8+^/V]  
boolean bStop = false; //Stop identical B,>02EZ  
FileAccessI fileAccessI = null; //File Access interface V DFgu  
.LzA'q1+z  
vq$6e*A  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `PWKA;W$0  
{ J)|3jbX"I]  
this.sURL = sURL; 5KC Qvv\  
this.nStartPos = nStart;  s*u A3}j  
this.nEndPos = nEnd; MAa9JA8kw)  
nThreadID = id; u~uzKG  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q):#6|u+  
} g"-j/ c   
K@.5   
Cfi{%,em  
public void run() s:T%, xS  
{ !3b& S4  
while(nStartPos < nEndPos && !bStop) -&/?&{Q0  
{ "x,lL  
8ro`lX*F@2  
=z1Lim-  
try{ ~ #jQFyOh  
URL url = new URL(sURL); H%_^Gy8f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q"d9C)Md  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8hGyh#  
String sProperty = "bytes="+nStartPos+"-"; y_X6{}Ke  
httpConnection.setRequestProperty("RANGE",sProperty); oz!)x\m*H  
Utility.log(sProperty); `z!AjAT-G  
o;8$#gyNY  
=s\$i0A2  
InputStream input = httpConnection.getInputStream(); w{ja*F6  
//logResponseHead(httpConnection);  _){|/Zd  
g/GI'8EMj  
+k`L8@a3&  
byte[] b = new byte[1024]; KzHN|8 $o  
int nRead; [LVXXjkFI  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |$WHw*F^  
{ j0l,1=^>l  
nStartPos += fileAccessI.write(b,0,nRead); 1?'4%>kp  
//if(nThreadID == 1) (UkP AE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pqG> |#RG  
} x@#>l8k?  
?2@^O=I  
jWdviS9&g  
Utility.log("Thread " + nThreadID + " is over!"); ;*%rFt9FK  
bDownOver = true; %\'=Y/yP  
//nPos = fileAccessI.write (b,0,nRead); ;c 7I "?@z  
} prJd'  
catch(Exception e){e.printStackTrace ();} ne#dEUD  
} '|C%X7  
} !Dd'*ee-;  
. ,|C>^  
e@3SF  
//打印回应的头信息 !LK xZ"  
public void logResponseHead(HttpURLConnection con) Ez1eGPVr  
{ 9< mMU:  
for(int i=1;;i++) Wn<?_}sa|z  
{ A7 RI&g v5  
String header=con.getHeaderFieldKey(i); *HrEh;3^J  
if(header!=null) }*x1e_m}H  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r8:r}Qj2w[  
Utility.log(header+" : "+con.getHeaderField(header)); /?.?1-HM  
else p6JTNx D  
break; g->*@%?<w>  
} Nl\`xl6y]  
} =, XCjiBeC  
@pH2"k| @  
#`Su3~T=S  
public void splitterStop() eWH0zswG  
{ ^O}a,  
bStop = true; tZ]gVgZg  
} 0cm34\*  
IMM;LC%rD9  
#|9W9\f,  
} XoN~d  
ZU 3Psj  
<H-Nft>O  
/* kpgvAKyx  
**FileAccess.java _S9)<RVI+  
*//文件访问(定位,写) 3lF"nv  
package NetFox; Nm)3   
import java.io.*; q1ysT.{p,  
)zL@h  
'_v~+  
public class FileAccessI implements Serializable{ V%-hP~nyBx  
V60L\?a  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q[OwP  
RandomAccessFile oSavedFile; .`D'eS6b  
long nPos; ItVN,sVJb  
fD!c t;UK  
G)vNMl  
public FileAccessI() throws IOException c7mKE`  
{ lY,^  
this("",0); eo+<@83  
} f-~Y  
~[CFs'`(2  
;L-=z]IR,  
public FileAccessI(String sName,long nPos) throws IOException 5=o^/Vkc  
{ KVZB`c$<t  
oSavedFile = new RandomAccessFile(sName,"rw"); <+QdBp'd;  
this.nPos = nPos; ZthT('"a  
oSavedFile.seek(nPos); JBY.er`6C  
} Nh\vWAz9  
'rhgM/I  
7(@xk_Pl  
public synchronized int write(byte[] b,int nStart,int nLen) yTZev|ej@  
{ |~Dl<#58  
int n = -1; Q}#Je.;  
try{ B&cIx~+  
oSavedFile.write(b,nStart,nLen); KZKE&bTx  
n = nLen; +bumWOQ'  
} b 3x|Dq.  
catch(IOException e) ^hLr9k   
{ _LJF:E5L  
e.printStackTrace (); 2yA)SGri  
} U[wx){[|  
~qinCIj  
9c^,v_W@  
return n; ~0MpB~ {xd  
} =E9\fRGU  
j_JY[sex  
Tpl]\L1v-  
} 0pE >O7  
D:T]$<=9  
i{^T;uAE  
/* K<P d.:  
**SiteInfoBean.java QFP9"FM5F  
*/ H )ej]DXy  
package NetFox; 868X/lL  
s%:fZ7y  
j[U#J  
public class SiteInfoBean { &g|[/~dIr  
|62` {+  
V'vWz`#  
private String sSiteURL; //Site's URL `'1g>Ebk0  
private String sFilePath; //Saved File's Path d]DV\*v  
private String sFileName; //Saved File's Name |5 V0_79  
private int nSplitter; //Count of Splited Downloading File [=K lDfU=  
I?rB7 *:  
 [ <X%  
public SiteInfoBean() A.>mk598  
{//nSplitter的缺省值为5 'rB% a<  
//default value of nSplitter is 5 [ U:C62oK,  
this("","","",5); JL6$7h  
} 4>,X.|9{  
GD4S/fn3  
NW1Jr/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y-ao yoNS  
{ UGAV"0  
sSiteURL= sURL; t6"%u3W8M  
sFilePath = sPath; C:B7%<  
sFileName = sName; |nNcV~%~  
this.nSplitter = nSpiltter; S f?;j{?G  
Vuz.b.,i`  
=F+v+zP7P  
} v~mVf.j1  
?+]=|hN  
p@jw)xI  
public String getSSiteURL() i.mv`u Dm  
{ M@ U >@x;  
return sSiteURL; OjGI !  
} !Se0&Ob  
%#2$B+  
03~ ADj  
public void setSSiteURL(String value) RqA>"[L  
{ JLu$1A@ '  
sSiteURL = value; rqjq}L)  
} g<Z :`00|  
R /=rNUe  
5m1J&TZ0  
public String getSFilePath() OHndZ$'fI  
{ 4\n ~  
return sFilePath; 3-/|G-4k7  
} ]y@A=nR  
Da-Lf2qT9  
d"XZlEV  
public void setSFilePath(String value) t'U=K>7  
{ eIvZhi  
sFilePath = value; phy}Hk/  
} +[G9PP6  
qHk{5O3  
w~@"r#-  
public String getSFileName() W\l&wR  
{ <{#_;7h"  
return sFileName; H~FI@Cf$L  
} 3X gJZ  
=mYf] PIX  
xSudDhRP  
public void setSFileName(String value) Xl4}S"a  
{ LhL |ETrJ  
sFileName = value; owIpn=8|Q  
} fOi Rstci  
<&\ng^Z$  
0q5J)l:  
public int getNSplitter() T<n`i~~  
{ xX&B&"]5  
return nSplitter; uU^DYgs  
} y-hTTd"{  
>M#@vIo?<6  
iM!2m$'s  
public void setNSplitter(int nCount) &qbEF3p^@  
{ |S!R Q-CF  
nSplitter = nCount; ):K%  
} ]o'o v  
} &GLDoLk6[  
Cfi4~&  
BdD]HXB|_  
/* %r|sb=(yT  
**Utility.java t=Oq<r  
*/ PaKa bPY  
package NetFox; i%o%bib#  
9Jwd*gevV  
Z:{| ?4  
public class Utility { p4P=T@:  
> 'R{,1# U  
7n5gXiI"  
public Utility() 9G[ DuYJI  
{ PSJj$bt;<+  
&@6xu{o  
Ll KO(Q{"  
} 4 {M   
 vm! y2  
//线程睡眠 JRB6T_U  
public static void sleep(int nSecond) M@T{uo  
{ v-#,@&Uwq  
try{ )+L|<6JXA  
Thread.sleep(nSecond);  Gsh9D  
} 3S3 a|_+%  
catch(Exception e) +<Gp >c  
{ MnD}i&k[  
e.printStackTrace (); 6_%Cd`4Z  
} 7L #)yY  
} no+ m.B  
|Z>-<]p9g  
//日志 i "V.$|,  
public static void log(String sMsg) )5@P|{FF  
{ ZQlk 5  
System.err.println(sMsg); 6)1PDlB  
} `dm*vd  
OkC.e')Vx  
vhF9|('G  
public static void log(int sMsg) +JI,6)Ry  
{ fd4gB6>  
System.err.println(sMsg); B :%Vq2`  
} 43k'96[2d  
} l0'Yq%Nf  
i@9 qp?eb  
45 ^ Z5t  
/* gs1yWnSv5  
**TestMethod.java A l;a~45  
*/ R([zlw~B5  
package NetFox; /%cDX:7X  
*Hx*s_F  
FF#Aq  
public class TestMethod { IFBt#]l0  
(wL$ h5SG  
u0#KBXRo  
public TestMethod() ( K[e=0Rf  
{ ///xx/weblogic60b2_win.exe e\X[\ve  
try{ /rpr_Xw}  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^1){ @(  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =bh: U90y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1{M?_~g 4  
fileFetch.start(); y CHOg  
} L-- t(G  
catch(Exception e){e.printStackTrace ();} r]Hrz'C`  
, LwinjHA*  
,<Cl^ ^a,  
} -,/7u3  
0y|1@CS  
s O#cJAfuu  
public static void main(String[] args) ~2>Adp  
{ "81'{\(I_  
new TestMethod(); <6;M\:Y*T  
} pmP~1=3  
} _Yo)m |RaB  
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:
10+5=?,请输入中文答案:十五