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
  • 8654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
/* Y A.&ap  
**SiteFileFetch.java L K&c~ Uy  
*/ |N,^*xP(6  
package NetFox; ;W0J  
import java.io.*; q 4BXrEOw  
import java.net.*; &oL"AJU  
xvGYd,dlK  
z/Lb1ND8  
public class SiteFileFetch extends Thread { * :"*'  
Ff<cY%t  
g4W$MI  
SiteInfoBean siteInfoBean = null; //文件信息Bean k-$Acv(  
long[] nStartPos; //开始位置 _z_YJ7A>  
long[] nEndPos; //结束位置 d`\SX(C  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 U$:^^Zt`B  
long nFileLength; //文件长度 01Jav~WR  
boolean bFirst = true; //是否第一次取文件 >N3X/8KL%  
boolean bStop = false; //停止标志 $G=^cNB|JB  
File tmpFile; //文件下载的临时信息 C&O8fNB_  
DataOutputStream output; //输出到文件的输出流 AArLNXzVW  
l&& i`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) LP3#f{U  
public SiteFileFetch(SiteInfoBean bean) throws IOException >^8O:.  
{ a-5UG#o  
siteInfoBean = bean; at>_EiS  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); T*p7[}#  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $.,PteYK  
if(tmpFile.exists ()) j;$f[@0o  
{ >iyNZ]."\  
bFirst = false; ``xm##K  
read_nPos(); ?[Yn<|  
} 5{H)r   
else wXNng(M7  
{ +:A `e+\  
nStartPos = new long[bean.getNSplitter()]; \mF-L,yu  
nEndPos = new long[bean.getNSplitter()]; <XL%*  
} 6 `6 I<OJ\  
|dIR v  
;5X6`GlS#5  
AB=%yM7V*  
} }#zL)+XI  
!&%KJS6p4  
pI@71~|R  
public void run() kn#?+Q  
{ 9WHE4'Sa  
//获得文件长度 Vy& X1lG:  
//分割文件 n'rq  
//实例FileSplitterFetch TF%n1H-sF  
//启动FileSplitterFetch线程 c((3B  
//等待子线程返回 (~|)Gmq2  
try{ lU 9o"2  
if(bFirst) |\bNFnn(  
{ c coi  
nFileLength = getFileSize(); 5a |R  
if(nFileLength == -1) 4lo7yx  
{ MpKXC   
System.err.println("File Length is not known!"); cg )(L;  
} CI+)0=`<1B  
else if(nFileLength == -2) x. t< @y~  
{ 8] LF{Obz[  
System.err.println("File is not access!"); ~'*23]j  
} 5?3v;B6  
else E2Sj IR}  
{ CW;zviH5  
for(int i=0;i<nStartPos.length;i++) CfOyHhhKX  
{ &4E|c[HN  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <v ub Q4  
} Cq@7oi]W0  
for(int i=0;i<nEndPos.length-1;i++) %>&~?zrq  
{ a,rXG  
nEndPos = nStartPos[i+1]; _9oKW;7f7  
} (R=ZI  
nEndPos[nEndPos.length-1] = nFileLength; #h ud_  
} `&I6=,YLp  
} ~ESw* 6s9  
j1Ys8k%$l  
{9J|\Zz3  
//启动子线程 W3l[a^1d  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d{TcjZ  
for(int i=0;i<nStartPos.length;i++) +@$VJM%^7b  
{ hl[<o<`Q  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yXkQ ,y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /{({f?k<\/  
nStartPos,nEndPos,i); C,;?`3bH@  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !,- 'wT<v  
fileSplitterFetch.start(); zGe =l;  
} fq1w <e  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6l|L/Z_6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :qS~"@?<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Qc33C A  
nEndPos = " + nFileLength); r E1ouz!D  
// fileSplitterFetch[nPos.length-1].start();  H#F"n"~$  
W}F~vx.  
f$</BND  
//等待子线程结束 t<`wK8)  
//int count = 0; s"7FmJ\7rw  
//是否结束while循环 *K>2B99TXu  
boolean breakWhile = false; 2U%t  
!:d\A  
#WA7}tHb  
while(!bStop) W)`>'X`  
{ EQnU:a  
write_nPos(); C&F% j.<  
Utility.sleep(500); [YQtX_;w  
breakWhile = true; oCwep^P(v  
bO6z;D#  
"-fyX!  
for(int i=0;i<nStartPos.length;i++) ~#EXb?#uS  
{ gISA13  
if(!fileSplitterFetch.bDownOver) Pf8_6z_  
{ [:,|g;=Y}  
breakWhile = false; ~+6#4<M.~  
break; C&q}&=3r  
} Uq=Rz8hLM  
} &WCVdZK:  
if(breakWhile) XffHF^l9F  
break; ;[zZI~wh  
`zs@W  
_2k<MiqCD[  
//count++; GDj_+G;tO\  
//if(count>4) ?,v@H$)3_  
// siteStop(); wPyc?:|KD?  
} ;J?fK69%  
^=I[uX-3ue  
sS)tSt{C  
System.err.println("文件下载结束!"); zv1,DnkqF  
} kPEU}Kv  
catch(Exception e){e.printStackTrace ();} 823y;  
} YC{7;=P f  
Vg (p_k45`  
uPFbKSJj  
//获得文件长度 9<Zm}PE32  
public long getFileSize() VQ~eg wJL  
{ 84(jg P  
int nFileLength = -1; 1_~'?'&^  
try{ PC=s:`Y}R  
URL url = new URL(siteInfoBean.getSSiteURL()); PVKq&Q?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N}|1oQkjf  
httpConnection.setRequestProperty("User-Agent","NetFox"); PHsM)V+  
NFU=PS$  
4yu=e;C wy  
int responseCode=httpConnection.getResponseCode(); D -e^b'l  
if(responseCode>=400) kSJ:4!lFU  
{ k \t6b1.M  
processErrorCode(responseCode); d76C ]R5L  
return -2; //-2 represent access is error Y5>'(A>  
} LQ$dT#z2A  
Xp^>SSt:4  
B]D51R\}VE  
String sHeader; X bV?=  
-r_Pp}s  
XF4NRs  
for(int i=1;;i++) RvW>kATb_F  
{ m[5ed1+  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lKirc2  
//Utility.log(in.readLine()); Qe<c@i"  
sHeader=httpConnection.getHeaderFieldKey(i); Tq6@ 1j6p  
if(sHeader!=null) QD[l 6  
{ IetV]Ff6  
if(sHeader.equals("Content-Length")) P.|g4EdND  
{ ~fA H6FdZ\  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,g)9ZP.F  
break; w68VOymD/  
} I>3G"[t  
} RML'C:1  
else Zfr?(y+3  
break; * 8D(Lp1  
} el0W0T  
} TwE&5F*  
catch(IOException e){e.printStackTrace ();} Lj3q?>D*^6  
catch(Exception e){e.printStackTrace ();} [h :FJ  
I'cM\^/h  
,wra f#UdP  
Utility.log(nFileLength); HQ|{!P\/?U  
LZ9IE>sj  
6~+?DIc  
return nFileLength; *Oe;JqQkK  
} 7w"YCRKh  
s&OwVQ<M  
rNHV  
//保存下载信息(文件指针位置) |z%*}DPrpa  
private void write_nPos() CV,[x[L# {  
{ qoD M!~  
try{ j[1^#kE  
output = new DataOutputStream(new FileOutputStream(tmpFile)); u`X}AKC  
output.writeInt(nStartPos.length); U#_rcu  
for(int i=0;i<nStartPos.length;i++) -Kf'02  
{ +%RXV ~  
// output.writeLong(nPos); `!T6#6h  
output.writeLong(fileSplitterFetch.nStartPos); 785Y*.p  
output.writeLong(fileSplitterFetch.nEndPos); 2|^bDg;W+u  
} ].w$b)G   
output.close(); 65A>p:OO  
} e.g$|C^$m  
catch(IOException e){e.printStackTrace ();} (3G]-  
catch(Exception e){e.printStackTrace ();} k@R)_,2HH  
} D#9W [6  
KK*"s^ L  
w4+bzdZ  
//读取保存的下载信息(文件指针位置) kjW`k?'s  
private void read_nPos() IF*kLl?  
{ {GH 0 J"  
try{ 1z(y>`ZBq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >&9Iy"  
int nCount = input.readInt(); C>7k|;BvF  
nStartPos = new long[nCount]; `qsn;  
nEndPos = new long[nCount]; eVWnD,'  
for(int i=0;i<nStartPos.length;i++) ]HP  
{ e{9(9qE"  
nStartPos = input.readLong(); A d7=JzV  
nEndPos = input.readLong(); [ !:.9  
} Hv>Hz*s_I  
input.close(); BO ^T :  
} =l3* { ?G  
catch(IOException e){e.printStackTrace ();} 3'6>zp  
catch(Exception e){e.printStackTrace ();} Z-j%``I?h  
} pr-!otz  
|5,q54d(K  
,G,T&W  
private void processErrorCode(int nErrorCode) e~we YGK  
{ {/ _.]Vh  
System.err.println("Error Code : " + nErrorCode); $NWI_F4  
} r).S/  
Fx0<!_tY-  
[OsW   
//停止文件下载 C`x>)wm:  
public void siteStop() 7b T5-=.  
{ m5LP~Gb  
bStop = true; DI!l.w5P_  
for(int i=0;i<nStartPos.length;i++)  Wcn^IQ  
fileSplitterFetch.splitterStop(); D058=}^HE  
B: uW(E  
'gE_xn7j  
} aARm nV  
} EY!aiH6P  
//负责部分文件的抓取 8DLMxG  
**FileSplitterFetch.java @,sg^KB  
*/ ? B^*YCo7(  
package NetFox; 4 ITSDx  
15gI-Qb  
Wm.SLr,o0  
import java.io.*; rq6(^I  
import java.net.*; p2 y h  
I)O-i_}L&K  
cEw/F0  
public class FileSplitterFetch extends Thread { {N;XjV1x  
5kJ>pb$/  
`h Y:F(  
String sURL; //File URL U]ouBG8/  
long nStartPos; //File Snippet Start Position +Mv0X%(N  
long nEndPos; //File Snippet End Position `^afbW  
int nThreadID; //Thread's ID J2H8r 'T  
boolean bDownOver = false; //Downing is over J(-#(kMyf  
boolean bStop = false; //Stop identical $X-,6*  
FileAccessI fileAccessI = null; //File Access interface Fu m1w  
^yu^Du  
f=J#mmH w$  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException  c:~o e  
{ Z!|nc.  
this.sURL = sURL; /)y~%0  
this.nStartPos = nStart; /{1xpR  
this.nEndPos = nEnd; mrd(\&EhA  
nThreadID = id; lTdYPqMi  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r"rID RQ"  
} Mp$ uEi  
hgKs[ySo,3  
"mT~_BsD  
public void run() bU:"dqRm<  
{ ^#%$?w>wI  
while(nStartPos < nEndPos && !bStop) sbNCviKP  
{ k2*^W&Z  
F+Lq  
WE`Y!  
try{ |vWx[=`o  
URL url = new URL(sURL); *+qXX CA  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jp5~iC2d  
httpConnection.setRequestProperty("User-Agent","NetFox"); S` X;2\:  
String sProperty = "bytes="+nStartPos+"-"; X'[S Cs  
httpConnection.setRequestProperty("RANGE",sProperty); T?7 ZF+yo6  
Utility.log(sProperty); OjeM#s#N!  
C2eei're  
j|HOry1E&  
InputStream input = httpConnection.getInputStream(); 6z=:x+m  
//logResponseHead(httpConnection); =UNzjmP503  
wTIOCj  
/2?GRwU~P  
byte[] b = new byte[1024]; Fz)z&WT  
int nRead; t_@%4Wn!1L  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {v]A`u)  
{ c+|,2e 0T  
nStartPos += fileAccessI.write(b,0,nRead); a50{gb#  
//if(nThreadID == 1) zc,fJM  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &sWq SS  
} U#,2et6  
XF{}St~(  
31YzTbl[H  
Utility.log("Thread " + nThreadID + " is over!"); le|e 4f*+  
bDownOver = true; d%4!d_I<  
//nPos = fileAccessI.write (b,0,nRead); 6]Ppa ~Xwq  
} tq>QZEg  
catch(Exception e){e.printStackTrace ();} eyl+D sK  
} ga~rllm;i  
} Sjj &n S  
qz(0iZ]Y  
Ge[N5N>  
//打印回应的头信息 S4`uNB#Ht  
public void logResponseHead(HttpURLConnection con) |{Z?a^- NJ  
{ PGu6hV{  
for(int i=1;;i++) =}U`q3k  
{ Alp9] 0(  
String header=con.getHeaderFieldKey(i); K}! VY`  
if(header!=null) ep,kImT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OYNs1yB  
Utility.log(header+" : "+con.getHeaderField(header)); ~XQN4Tv-  
else a{69JY5  
break; (? YTQ8QR  
} +&-/$\"  
} nvsuF)%9hZ  
Kv!CL9^LX7  
nY}Ep\g  
public void splitterStop() i v&:X3iB  
{ Gv6EJV1i  
bStop = true; ],&WA?>G  
} >,A:zbs&  
vQ26U(7\>  
qeSxE`E"  
} I`E9]b(w  
>K;p+( <6  
8KT|ixs  
/* m[Px|A5{  
**FileAccess.java m_Z%[@L  
*//文件访问(定位,写) XrtB&h|C  
package NetFox; }N*6xr*X+  
import java.io.*; i@Q)`>4  
4wMKl6mL  
LYkW2h`JQ  
public class FileAccessI implements Serializable{ *w59BO&M4  
0b~5i-zM/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y*B}^!k6  
RandomAccessFile oSavedFile; {Qg"1+hhM  
long nPos; E,u@,= j  
L5of(gQ5]  
\BbemCPAm  
public FileAccessI() throws IOException "f(iQI  
{ z';p275  
this("",0); r^VH [c@c  
} !ZD[ $lt+  
n4qj"x Q  
.& B_\*  
public FileAccessI(String sName,long nPos) throws IOException %{5mkO&,2  
{ FSIV\ u  
oSavedFile = new RandomAccessFile(sName,"rw"); d1D{wZ3g  
this.nPos = nPos; RAR"9 N .  
oSavedFile.seek(nPos); $2 ~RZpS  
} `8KWZi4 ]  
2zh?]if  
b,$H!V *  
public synchronized int write(byte[] b,int nStart,int nLen) #ZRQVC;b;  
{ QOcB ]G  
int n = -1; G?8LYg!-  
try{ ePa1 @dI  
oSavedFile.write(b,nStart,nLen); \ :1MM  
n = nLen; $F`jM/B6  
} 8 POrD8B  
catch(IOException e) J,_I$* _0  
{ k6QQoLb$V  
e.printStackTrace (); T`Sp!  
} BPIp3i  
smF#'"{  
8AOJ'~$  
return n; 8sx\b  
} P'KaWu9z  
(SfP3  
12~zS  
} wtndXhVC4>  
\3hhM}6)DM  
[58xT>5`m  
/* 5<<e_n.2q  
**SiteInfoBean.java <}pqj3  
*/ a9(1 6k  
package NetFox; Aj*0nV9_  
]tanvJG}'  
>w9fFm!Q  
public class SiteInfoBean { ~2beVQ(U  
UsNr$MO {  
d>M&jSCL  
private String sSiteURL; //Site's URL ;m,lS_[c  
private String sFilePath; //Saved File's Path MP-A^QT  
private String sFileName; //Saved File's Name J@=1zL  
private int nSplitter; //Count of Splited Downloading File KCGs*kp>  
/iQ}DbtRb  
&G@(f=  
public SiteInfoBean() Y [0 S  
{//nSplitter的缺省值为5 BBm.;=8@ ^  
//default value of nSplitter is 5 <fCgU&  
this("","","",5); t7H2z}06=h  
} Yc3r 3Jy  
{l-,Jbfi`  
KN'l/9.  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Vrf2%$g  
{ |qE"60&"}  
sSiteURL= sURL; 1c(1YGuH  
sFilePath = sPath; MGCwT@P  
sFileName = sName; ^VR1whCrx  
this.nSplitter = nSpiltter; 8*;G\$+  
Z=_p  
wciYv,  
} U59uP 7n  
.taJCE  
#r `hK)  
public String getSSiteURL() R4"["T+L`  
{ LS{g=3P0  
return sSiteURL; zU:zzT}|TZ  
} v(3nBZHv_!  
a.v$+}+.[,  
GrGgR7eC#P  
public void setSSiteURL(String value) X4>c(1e  
{ h `d(?1  
sSiteURL = value; su<_?'uH  
} VZ &>zF  
LDN'o1$qo  
sZ{Kl\1@  
public String getSFilePath() =iC5um:  
{ [R)?93  
return sFilePath; Q*+@"tk<  
} E j@M\  
)#l &F$  
hun L V8z  
public void setSFilePath(String value) a5{CkM&,(  
{ yb1A(~  
sFilePath = value; .^N+'g  
} *,-)4)7d  
-@b&qi7&S  
MeW8aL r  
public String getSFileName() m=k(6  
{ !s/ij' T  
return sFileName; %@'9<i8o  
} + V4BJ/H  
o^wj_#ai$  
WZ&/l 65J  
public void setSFileName(String value) - o$S=  
{ 6cp x1y]~6  
sFileName = value; +j_Vs+0  
} XL_X0(AKf  
"5Bga jrB  
eC%.xu^  
public int getNSplitter() Zk$AAjC&  
{ ZalG/PFy  
return nSplitter; KS}Ci-  
} .Ej `!  
-wtavv,J  
fw ._  
public void setNSplitter(int nCount) W%hdS<b  
{ J)Dw`=O0n  
nSplitter = nCount; }UMg ph:2:  
} 4NUCLr7Y  
} e2*0NT^R  
9-eYCg7C|  
1 h|cr_  
/* E)o/C(g  
**Utility.java HuBG?4Qd  
*/ &NZN_%  
package NetFox; r+3V+:f  
FjRJSMwO,  
*Af]?-|^{#  
public class Utility { :T" !6;  
 T/p}Us  
Wznz  
public Utility() )TJz'J\*  
{ 9Gfm?.O5  
s@OCj0'l  
X ~%I(?OX  
} @y[Zr6\z  
L^yQb4$&M  
//线程睡眠 E D*=8 s2  
public static void sleep(int nSecond) Ij(S"P@  
{ YN_#x  
try{ RQWVjF#  
Thread.sleep(nSecond); t }7hD  
} PwQW5,,h0  
catch(Exception e) ,w,>pO'[  
{ #R4Mv(BG  
e.printStackTrace (); I: U/%cr,  
} 7f8%WD)  
} H[@uE*W  
TyD*m$`y  
//日志 \)eHf 7H  
public static void log(String sMsg) ~0w7E0DE[  
{ J5)e 7  
System.err.println(sMsg); ,w; ~R4x  
} VQU[5C  
C6,GgDH`  
LO[1xE9  
public static void log(int sMsg) eW"i'\`0  
{ {/uBZ(   
System.err.println(sMsg); W:O<9ZbQ_  
} ~:b bV6YO  
} F7^8Ej9*a  
e &^BPzg  
t1b$,jHmKl  
/* YN?@ S  
**TestMethod.java L!V`Sb  
*/ 3H%R`ha  
package NetFox; jWLZ!a3+  
.{`+bT^b<2  
qGuz`&i  
public class TestMethod { jFM8dl n  
0*L|r Jf  
`!S5FE"-  
public TestMethod() wYSvI  
{ ///xx/weblogic60b2_win.exe 4q/E7n  
try{ Fkuq'C<|Y  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D;Fvd:  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >9a%"<(2#  
SiteFileFetch fileFetch = new SiteFileFetch(bean); V"%2Tz  
fileFetch.start(); -}%'I ]R=  
} R"6Gm67t  
catch(Exception e){e.printStackTrace ();} Kv:UQdnU[  
>s1FTB-$W  
&JAQ:([:  
} J_}&Btb)e  
6#T?g7\pyR  
|w- tkkS  
public static void main(String[] args) [6V'UI6  
{ ><"5 VwR  
new TestMethod(); K~<pD:s  
} $Rv}L'L  
} ?Pw# !t  
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