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
  • 7308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
/* d`4@aoM  
**SiteFileFetch.java z`rW2UO#a`  
*/ .(8eWc YK  
package NetFox; W/I D8+:i  
import java.io.*; +\`t@Ht#  
import java.net.*; h}(GOY S)  
t%>x}b"2T  
U})Z4>[bvt  
public class SiteFileFetch extends Thread { [=I==?2`X  
p9$=."5  
&T/}|3S  
SiteInfoBean siteInfoBean = null; //文件信息Bean HA%r:Px  
long[] nStartPos; //开始位置 xDBHnr}[  
long[] nEndPos; //结束位置 q5(Z   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 )v?-[ oR  
long nFileLength; //文件长度 TANt*r7  
boolean bFirst = true; //是否第一次取文件 AehkEN&H/t  
boolean bStop = false; //停止标志 @](\cT64i3  
File tmpFile; //文件下载的临时信息 r<L>~S>yb  
DataOutputStream output; //输出到文件的输出流 ='|HUxFi  
HxH=~B1"P  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) s_N]$3'[E  
public SiteFileFetch(SiteInfoBean bean) throws IOException h^6Yjy  
{ 2VNfnk  
siteInfoBean = bean; #2*2xt  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); t#[u X?  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); lw"5p)aB  
if(tmpFile.exists ()) A4uDuB;;ZQ  
{ ,\ RxKSU  
bFirst = false; k@= LR  
read_nPos(); P(BV J_n  
} Z<0+<tt  
else M.R] hI  
{ N%&D(_  
nStartPos = new long[bean.getNSplitter()]; )C CrO   
nEndPos = new long[bean.getNSplitter()]; V2?&3Z) W  
} xd`!z`X!,s  
!56gJJ-r  
A/"p PO  
2i~qihx5^  
} \V,;F!*#G  
)\TI^%s  
ku}I; k |  
public void run() l6Q75i)eF  
{ #GHLF  
//获得文件长度 ]xIfgSq  
//分割文件 [#R<Z+c  
//实例FileSplitterFetch NCM&6<_  
//启动FileSplitterFetch线程 (^Kcyag4  
//等待子线程返回 zl !`*{T{  
try{ U'acVcD  
if(bFirst) 1$Pn;jg:  
{ h8!;RN[  
nFileLength = getFileSize(); KGm"-W  
if(nFileLength == -1) W<D(M.61A  
{ 7+I2" Hy  
System.err.println("File Length is not known!"); {E~ MqrX  
} pQ Y.MZSA  
else if(nFileLength == -2) wB;'+d&  
{ q:1_D>  
System.err.println("File is not access!"); z!I(B^)BkT  
} 5Y8/ZW~D0  
else R]Q4+  
{ 5PQs1B  
for(int i=0;i<nStartPos.length;i++) =Jx,.|Bf  
{ 1=t\|Th-  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ZkJYPXdn?  
} jF\J+:5M  
for(int i=0;i<nEndPos.length-1;i++) I!;#Nk>  
{ ,e ~@  
nEndPos = nStartPos[i+1]; [T.BK:  
} .baS mfc  
nEndPos[nEndPos.length-1] = nFileLength; i%~4>k  
} :>[;XT<  
} 5)yQrS !{:  
tU%-tlU9?  
^m   
//启动子线程 EO;f`s)t  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fx QN  
for(int i=0;i<nStartPos.length;i++) ?7cF_Zvve  
{ j}?O  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }>:x  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /.\$%bua  
nStartPos,nEndPos,i); khb Gyg%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X3:-+]6,d  
fileSplitterFetch.start(); j]"Yz t~u  
} jz$)*Kdi*  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -< 7KW0CA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R?Q@)POW  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +*Cg2`  
nEndPos = " + nFileLength); 8<t?o'9I  
// fileSplitterFetch[nPos.length-1].start(); K`@GN T&  
eb)S<%R/  
`C`_2y8  
//等待子线程结束 h<9h2  
//int count = 0; h(I~HZ[K&T  
//是否结束while循环 T] nZ3EZ  
boolean breakWhile = false; 3X{=* wvt  
)(&g\  
X!n-nms  
while(!bStop) Kk~0jP_B9  
{ Qko}rd_M  
write_nPos(); f#l/N%VoBZ  
Utility.sleep(500); PL8eM]XS  
breakWhile = true; 'B"kUh%3$5  
d& @KGJ  
~`MGXd"o  
for(int i=0;i<nStartPos.length;i++)  jK&kQ  
{ x]k^JPX  
if(!fileSplitterFetch.bDownOver) IrXC/?^h  
{ n\ma5"n0=\  
breakWhile = false; F,e_`  
break; I/GZ  
} %f@VOSs  
} &,fBg6A%  
if(breakWhile) Z$,1Tk"O/s  
break; SF;;4og  
8jjJ/Mz`  
fj 19U9R  
//count++; r&\}E+  
//if(count>4) E<a~ `e  
// siteStop(); KTk%N p  
} WZCX&ui  
{ >Y<!  
Ckvm3r\i2  
System.err.println("文件下载结束!"); mB#`{|1[  
} ;X\>oV3#  
catch(Exception e){e.printStackTrace ();} Vd|5JA}<"  
} X63DBF4A  
o"v> BhpC  
$<]y.nr|CX  
//获得文件长度 D;<Q m,[  
public long getFileSize() _qmB PUx  
{ ~]A';xH&  
int nFileLength = -1; 2u6N';jgZ  
try{ DnaG$a<  
URL url = new URL(siteInfoBean.getSSiteURL()); / v;g v[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }{Lf 4|8  
httpConnection.setRequestProperty("User-Agent","NetFox"); -b(:kAwStk  
[/*85 4  
"aP>}5<h  
int responseCode=httpConnection.getResponseCode(); E+"INX7  
if(responseCode>=400) sj`9O-?49  
{ (>>pla^  
processErrorCode(responseCode); T_,LK7D  
return -2; //-2 represent access is error A A<9 XC  
} ;oULtQ  
-NZj :N  
:M ix*NCf  
String sHeader; Qkk~{OuC  
_?@>S7-  
vUgLWd  
for(int i=1;;i++) {TdK S  
{ 6yTL7@V|B  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tZU"Ud  
//Utility.log(in.readLine()); A@_F ;4X  
sHeader=httpConnection.getHeaderFieldKey(i); Z[AJat@H  
if(sHeader!=null) E] t:_v  
{ 4lb3quY$Us  
if(sHeader.equals("Content-Length")) rg_-gZl8&z  
{ ^=D77 jS  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _ZD)#?  
break; +B_q? 6pR  
} Roy`HU ;0a  
} rQ*'2Zf'<  
else Q_6./.GQ  
break; P}&7G-  
} C3bZ3vcW$  
} ?GD{}f33  
catch(IOException e){e.printStackTrace ();} 5HL JkOV5  
catch(Exception e){e.printStackTrace ();}  h:#  
>}O1lsjW:z  
YIfPE{,  
Utility.log(nFileLength); v2EM| Q xp  
{)ZbOq2  
\ fU{$  
return nFileLength; x7Ly,  
} zmf5!77  
Lvv`_  
w*#k&N[X  
//保存下载信息(文件指针位置) x;Dr40wD@y  
private void write_nPos() u/ y`M]17  
{ #&r^~>,#L-  
try{ AWQwpaj-  
output = new DataOutputStream(new FileOutputStream(tmpFile)); +VDl"Hx  
output.writeInt(nStartPos.length); 9qwVBu ;  
for(int i=0;i<nStartPos.length;i++) -1S+fUkiK/  
{ wXXv0OzK  
// output.writeLong(nPos); B Ibcm,YQ  
output.writeLong(fileSplitterFetch.nStartPos); uTP=kgYqJ  
output.writeLong(fileSplitterFetch.nEndPos); jDgiH}  
} ^bL.|vB  
output.close(); eiP>?8  
} )@1_Dm@0b  
catch(IOException e){e.printStackTrace ();} pwd7I  
catch(Exception e){e.printStackTrace ();} 0gO2^m)W  
} kZ`60X%wE  
_4zlEo-.gU  
|KU>+4= @  
//读取保存的下载信息(文件指针位置) Zf]d'oW{/  
private void read_nPos() TDtk'=;  
{ Lkk'y})/  
try{ yn!LJT[~2  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;n7k_K#0z!  
int nCount = input.readInt(); %>xW_5;Z  
nStartPos = new long[nCount]; &E {/s  
nEndPos = new long[nCount]; 6$)Yqg`X  
for(int i=0;i<nStartPos.length;i++) L V33vy  
{ ;c:vz F~Q  
nStartPos = input.readLong(); 0[PP Vr:  
nEndPos = input.readLong(); fgn*3 pg  
} kt X(\Hf!  
input.close(); xE;fM\7pu  
} o0s+ roiD  
catch(IOException e){e.printStackTrace ();} X_Y$-I$qd  
catch(Exception e){e.printStackTrace ();} ,!%[CpM3  
} $3Wl~ G}  
X[NsdD?w1+  
kfm8F8sxl  
private void processErrorCode(int nErrorCode) jW2z3.w  
{ pl q$t/.U;  
System.err.println("Error Code : " + nErrorCode); WF*2^iWJ  
} OYG8%L  
7gD$Q  
W1r-uR  
//停止文件下载 @U5 +1Hjc  
public void siteStop() _jU6[y|XLh  
{ cQgmRHZ]  
bStop = true; H0tjN&O_  
for(int i=0;i<nStartPos.length;i++) )u\"xxcV  
fileSplitterFetch.splitterStop(); <&l3bL  
A8c'CMEm  
4X#>;  
} Pm+H!x,  
} z56W5g2  
//负责部分文件的抓取 *tz"T-6O  
**FileSplitterFetch.java _Mq@58q'  
*/ .HZYSY:X  
package NetFox; x*BfRj  
1K^/@^  
6<]&T lS]  
import java.io.*;  <MvFAuAT  
import java.net.*; f_D1zU^  
Q(V c/  
]jY->NsA]  
public class FileSplitterFetch extends Thread { M9bb,`X>Q  
l4R:_Z<  
{*jkx,|  
String sURL; //File URL v8 6ls[lzu  
long nStartPos; //File Snippet Start Position z ; :E~;  
long nEndPos; //File Snippet End Position zFB$^)v"<  
int nThreadID; //Thread's ID z<^HohT  
boolean bDownOver = false; //Downing is over tBrd+}e2*  
boolean bStop = false; //Stop identical Q9%N>h9  
FileAccessI fileAccessI = null; //File Access interface VD36ce9  
]>R`]U9*O  
^!pagt^  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _6=6 b!hD  
{ .%WbXs  
this.sURL = sURL; ^Y #?@  
this.nStartPos = nStart; 0qJ(3N  
this.nEndPos = nEnd; 0p Lb<&  
nThreadID = id; Q$kSK+ q!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,"j |0Q  
} .O1g'%  
CCl*v  
t&0n"4$d'  
public void run() A[oi?.D  
{ 5f}63as  
while(nStartPos < nEndPos && !bStop) G _42ckLq  
{ 2+"#  
@*%5"~F  
@zd)]O]xH?  
try{ dBobVT'  
URL url = new URL(sURL); ;zSh9H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O;qS 3  
httpConnection.setRequestProperty("User-Agent","NetFox"); H1hj` '\"<  
String sProperty = "bytes="+nStartPos+"-"; ym(r;mj!  
httpConnection.setRequestProperty("RANGE",sProperty); o5Pq>Y2T  
Utility.log(sProperty); uo 7AU3\  
HpNf f0c  
k*z)AR  
InputStream input = httpConnection.getInputStream(); \P{VJ^) 0  
//logResponseHead(httpConnection); H~||]_q|  
[0MVsc=  
Ae`K 9  
byte[] b = new byte[1024]; s'} oVx]  
int nRead; gtCd#t'(V  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `n5 )oU2q  
{ !n)2HDYhx,  
nStartPos += fileAccessI.write(b,0,nRead); /7P4[~vw  
//if(nThreadID == 1) eW7;yH  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "V?U^L>SF  
} \i`/k(  
q'K=Ly+  
HK:?Y[ebs  
Utility.log("Thread " + nThreadID + " is over!"); T:na\y/{j  
bDownOver = true; f>p;Jh{2fn  
//nPos = fileAccessI.write (b,0,nRead); =P0~=UP  
} bh uA,}  
catch(Exception e){e.printStackTrace ();} J,+| Fb  
} G.T}^ xHmL  
} 0%'&s)#  
^(UL$cQ>  
'H*S-d6V  
//打印回应的头信息 6AZ/whn#  
public void logResponseHead(HttpURLConnection con) Pfi '+I`s  
{ AbLOq@lrK  
for(int i=1;;i++) ;znIY&Z  
{ tM{t'WU  
String header=con.getHeaderFieldKey(i); --  _,;  
if(header!=null) ZHw)N&Qn  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Y}(v( (;  
Utility.log(header+" : "+con.getHeaderField(header)); e[R364K  
else #XC\= pZX  
break; ">CjnF2>R  
} q| gG{9  
} [gH vI  
=<a`G3SY!  
W~dS8B=<  
public void splitterStop() j6IWdqXe  
{ Et`z7Q*e  
bStop = true; }@a_x,O/x}  
} #.Ft PR  
f4`=yj*  
uN6TV*]:  
} Wl::tgU  
P) GBuW  
\t^q@}~0Wz  
/* ]hv4EL(zi  
**FileAccess.java `){*JPl  
*//文件访问(定位,写) mv<z%y?Oj  
package NetFox; gt'0B-;W  
import java.io.*; i (L;1 `  
obaJT"1  
\gj@O5rGP  
public class FileAccessI implements Serializable{ }2V|B4  
3x 'BMAA+  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *Swb40L^  
RandomAccessFile oSavedFile; b/5;377_  
long nPos; /-G;#Wm  
~G5)ya-  
<\2,7K{{+;  
public FileAccessI() throws IOException H4^-MSw  
{ X^fMt]  
this("",0); }MXZ  
} yv4hH4Io  
",`fGu )  
y\r8_rBo  
public FileAccessI(String sName,long nPos) throws IOException jIAl7aoY  
{ ZqS'xN :k  
oSavedFile = new RandomAccessFile(sName,"rw"); X#gZgz ='  
this.nPos = nPos; !t~S.`vF  
oSavedFile.seek(nPos); 3vNoD  
} |2{y'?,  
Mq6.!j  
.CrahV1G  
public synchronized int write(byte[] b,int nStart,int nLen) :m^eNS6:  
{ C!RxMccTh  
int n = -1; GwW!Q|tVz=  
try{ im4V6 f;%  
oSavedFile.write(b,nStart,nLen); YX!%R]c%  
n = nLen; }T4"#'`  
} ##1[/D(  
catch(IOException e) MP;7 u%   
{ Dr,{V6^  
e.printStackTrace (); Fgt/A#`fz  
} v[35C]gS  
u|O5ZV-cd  
2+ >.Z.pX  
return n; Yz\z Qj  
} jJ|u!a  
3DMfR ofg  
VX2bC(E'%  
} vr=iG xD  
7GWPsaPn  
IkL|bV3E0  
/* O^F%ssF8  
**SiteInfoBean.java AEOo]b*&d  
*/ Aj SIM.  
package NetFox; ~*THL0]~  
,? <jue/bd  
OUnt?[U\  
public class SiteInfoBean { o&fAnpia=  
76mQ$ze  
{C|#<}1  
private String sSiteURL; //Site's URL ZMy7z|  
private String sFilePath; //Saved File's Path z Sj.Y{J  
private String sFileName; //Saved File's Name nWmc  
private int nSplitter; //Count of Splited Downloading File tjuW+5O  
!$qNugLg  
p,$1%/m  
public SiteInfoBean() {cq; SH  
{//nSplitter的缺省值为5 :$dGcX}  
//default value of nSplitter is 5 E3_EXz9 h  
this("","","",5); j?[fpN$  
} V ,*YM   
}!lLA4XRr  
[$OD+@~A2  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2 ,E&}a|;b  
{ Pm%ZzU  
sSiteURL= sURL; h,rGa\X~0  
sFilePath = sPath; kIP~XV~  
sFileName = sName; b ]1SuL  
this.nSplitter = nSpiltter; _I3j 7f,V  
9\R:J"X  
2AzF@Pi^z  
} .LN&EfMenF  
+, p  
L8T T54fM  
public String getSSiteURL() u}qfwVX Z  
{ DIkD6n?V  
return sSiteURL; :sk7`7v  
} %:YON,1b=7  
p_!Y:\a5  
E9!IGci  
public void setSSiteURL(String value) ofj7$se  
{ g@`14U/|  
sSiteURL = value; K3!|k(jt  
} M)V z9,  
TM[Z~n(wt  
Ep.,2H  
public String getSFilePath() #xm<|s   
{ Cdot l$'  
return sFilePath; _ZC4O&fL  
} D0~WK stl  
?b^VEp.;}  
t`Mm  
public void setSFilePath(String value) TB*g$ *  
{ 1CFrV=d  
sFilePath = value; toX4kmC  
} `m`jX|`  
*x)WF;(]g  
M5: f^  
public String getSFileName() k_-=:(Z  
{ lVARe3#  
return sFileName; 2:&8FdU  
} i8Yl1nF  
7==Uz?}C  
ipw_AC~  
public void setSFileName(String value) aVO5zR./)  
{ ]J~37 35]  
sFileName = value; s~IOc%3  
} N 2L/A  
G0^23j  
Y^2`)':  
public int getNSplitter() {!o-y=  
{ Qh? E* 9  
return nSplitter; p%]* I?  
} de[c3!#1d  
4ME8NEE  
 C!Y|k.`p  
public void setNSplitter(int nCount) {{tH$j?Q  
{ G>YJ3p7  
nSplitter = nCount; DSizr4R  
} *;,=x<  
} !})/x~~e  
@zT.&1;`  
n-}:D<\7  
/* yodJGGAzk  
**Utility.java 4+$<G/K  
*/ ;=5V)1~i1;  
package NetFox; NQ'^ z  
B5  C]4  
?0DCjh8We  
public class Utility { #fk)Y1  
/ h0-qW  
ie 2X.#  
public Utility() 5w@  ;B  
{ DcQ^V4_  
oZA|IF8U0  
A0V"5syY  
} wkdd&Nw;  
F$ZWQ9&5U0  
//线程睡眠 PxfeU2^{0  
public static void sleep(int nSecond) SL hki)|  
{ y$r9Y!?s  
try{ U^+9l?ol  
Thread.sleep(nSecond); ?" {+m  
} ga4 gH>4  
catch(Exception e) 83412@&  
{ )XnG.T{0|  
e.printStackTrace (); HsR#dp+s~  
} @1*lmFq'kV  
} ,b-wo  
k]qZOO}  
//日志 ,au64sH  
public static void log(String sMsg) &VY;Al  
{ 9(|[okB  
System.err.println(sMsg); kZU8s'C  
} `]LaX&u  
>BrxJw#M  
E&{*{u4  
public static void log(int sMsg) `y P-,lA$  
{ "f!*%SR: 1  
System.err.println(sMsg); c72Oy+#  
} q-o=lU"  
} #_2V@F+,  
$\81WsL '  
Eh!%Ne O  
/* AU^Wy|i5Q  
**TestMethod.java ~H@':Mms.h  
*/ y z9`1R2c  
package NetFox; KfG%#2\G_  
_8 vxb  
bjm`u3 A  
public class TestMethod { \#LKsQa  
,*E%D _  
J}._v\Q7P  
public TestMethod() @tEVgyN  
{ ///xx/weblogic60b2_win.exe E;VBoN [  
try{ ;FMK>%Zq  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); thipfS  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %f6l"~y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); w?jmi~6  
fileFetch.start();  7z<!2  
} /nv1 .c)k  
catch(Exception e){e.printStackTrace ();} reu[}k~  
IH\k_Yf#u  
iBp 71x65  
} P^rSpS9  
E0xUEAO  
$rFv(Qc^=  
public static void main(String[] args) 9'8OGCN  
{ By3dRiM=,2  
new TestMethod(); F|xXMpC.f  
} @h>#cwhU  
} zHb<YpU  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八