http断点续传简单实现（java)

亚文隆

级别: 经院学前班

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

只看楼主更多操作楼层直达

0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); X\I"%6$
} QzwA*\G
for(int i=0;i<nEndPos.length-1;i++) ~olta\|
{ k-v@sb24_
nEndPos = nStartPos[i+1]; em87`Hj^lo
} 7,sslf2%K
nEndPos[nEndPos.length-1] = nFileLength; FE)L?
} (5SN=6O
} B/(]AWi+
M``I5r*cg
eQ}o;vJN
//启动子线程 Btmv{'T_y@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *}t,:N;i
for(int i=0;i<nStartPos.length;i++) )1KlcF
{ BCE}Er&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i#@3\&{J>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v.08,P{b
nStartPos,nEndPos,i); +$eEZ;4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yxal%
fileSplitterFetch.start(); xp395ub6
} -`mHb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8?lp:kM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UqaLTdYG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %n3lm(-0U
nEndPos = " + nFileLength); Lh%>> Ht{
// fileSplitterFetch[nPos.length-1].start(); }*2q7K2bj
z;dD }Fo
#1:&uC1vj
//等待子线程结束 PXZZPW/
//int count = 0; d$uh.?F5
//是否结束while循环 (f^K\7HM
boolean breakWhile = false; ~*|0yPFg
t?1+Yw./em
Zd/ACZ[
while(!bStop) cG|ihG5)
{ MYzyg
write_nPos(); .[v4'ww^
Utility.sleep(500); ,8KD-"l^g
breakWhile = true; 'V reO52
H!y%FaTi
zCdQI
for(int i=0;i<nStartPos.length;i++) DK/xHIv8-
{ +H[GD!
if(!fileSplitterFetch.bDownOver) Nw`}iR0i
{ cxhS*"Ph
breakWhile = false; qwlIz/j
break; 7|A9
} D\~*| J
} RcUKe,
if(breakWhile) -q9`Btz
break; `ySmzp
C F2*W).+
nVqFCBB
//count++; -r9G5Z!|n
//if(count>4) x0ZEVa0`4
// siteStop(); F2/-Wk@
} Rc2|o.'y
'CqWF"
RCED K\*m
System.err.println("文件下载结束！"); #tyHjk
} U"} ml
catch(Exception e){e.printStackTrace ();} #]ZOi`;
} =='~g~
VU1;ZJE
6vVx>hFJ47
//获得文件长度 wl1JKiodg
public long getFileSize() bgW=.s
{ K)|#FRPM u
int nFileLength = -1; 6{rH|Z
try{ fqaysy
URL url = new URL(siteInfoBean.getSSiteURL()); 5>J{JW|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s6k,'`.
httpConnection.setRequestProperty("User-Agent","NetFox"); 6~Y-bn"%D5
"(uEcS2<
hjB G`S#
int responseCode=httpConnection.getResponseCode(); 4}:a"1P"
if(responseCode>=400) o#X|4bES
{ _ri1RK,
processErrorCode(responseCode); Is~bA_- ;
return -2; //-2 represent access is error F&r+"O)^-R
} v3w5+F
-lM4*+f
{'W\~GnZ
String sHeader; *@J
\29a@6
6Sh0%Fs
for(int i=1;;i++) &j}\ZD
{ qGtXReK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =;.#Bds
//Utility.log(in.readLine()); `3!ERQU
sHeader=httpConnection.getHeaderFieldKey(i); 9QaEUy*,
if(sHeader!=null) #t /.fd
{ {K-]nh/
if(sHeader.equals("Content-Length")) d[+xLa
{ [4:_6vd7X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jHPJk8@y
break; #/'5N|?
} )Yvf9dl
} $ig%YB
else .W{\wkn
break; JV|GEn\@N
} C<CE!|sfr
} k$nQY
catch(IOException e){e.printStackTrace ();} RsJj*REO
catch(Exception e){e.printStackTrace ();} y0vo-)E]-]
g2b%.X4
0r=:l/Pz
Utility.log(nFileLength); =:rR%L!a
IS0RhtGy/
~c7}eTJd"
return nFileLength; S_cba(0-|\
} MF/359r)Et
1<_i7.{k
<lh+mrXm
//保存下载信息（文件指针位置） 24_F`" :-=
private void write_nPos() g_Wf3o857J
{ 8M m,a
try{ S/CT;M@W
output = new DataOutputStream(new FileOutputStream(tmpFile)); "WOY`su>
output.writeInt(nStartPos.length); Pb$ep|`u
for(int i=0;i<nStartPos.length;i++) o.DT`L8
{ -[?q?w!?
// output.writeLong(nPos); ,o-BJ 069
output.writeLong(fileSplitterFetch.nStartPos); H"W%+{AR
output.writeLong(fileSplitterFetch.nEndPos); $FEG0&
} CK1Xdyf_S
output.close(); 6y&d\_?Y
} '|n-w\ >Wv
catch(IOException e){e.printStackTrace ();} Hw8`/'M=%5
catch(Exception e){e.printStackTrace ();} cF_hU"
} b'`8$;MII
GuMsw*{>
k WYjqv
//读取保存的下载信息（文件指针位置） 2`,{IHu*!
private void read_nPos() 0IoS|P}6a
{ IH?.s k
try{ F,^Q'$!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HaI
int nCount = input.readInt(); /C29^P
nStartPos = new long[nCount]; IbAGnl{
nEndPos = new long[nCount]; $-9m8}U(Y
for(int i=0;i<nStartPos.length;i++) R?g qPi-
{ qy6zHw
nStartPos = input.readLong(); b`E'MX_ m
nEndPos = input.readLong(); 3e$&rpv
} g9OO#C>
input.close(); HgY"nrogt$
} dE2(PQb*P
catch(IOException e){e.printStackTrace ();} X"<t3l(+
catch(Exception e){e.printStackTrace ();} dV#h~
} g]O"l?xx1D
;bq_Y/"
)6dvWK
private void processErrorCode(int nErrorCode) %76N$`{u
{ n\aG@X%oq
System.err.println("Error Code : " + nErrorCode); f,z_|e
} }./__gJ
9/R|\
S!o!NSn@1
//停止文件下载 :WejY`}H%
public void siteStop() O$+J{@
{ {4tJT25
bStop = true; [aX'eMq
for(int i=0;i<nStartPos.length;i++) p%5RE%u
fileSplitterFetch.splitterStop(); 3B95t-
-%"Kxe
_ v\=ag
} MnUal}MO
} -#=v~vE
//负责部分文件的抓取 z>+@pj
**FileSplitterFetch.java lil1$K: i
*/ a%DnRkRr
package NetFox; D]resk
ZZp6@@zyq'
I$v*SeVHE
import java.io.*; 75}BI&t3k
import java.net.*; Yd:8iJA
fLl~a[(5
ai[st+1
public class FileSplitterFetch extends Thread { WP7*Q:5
4Y8/>uL
A?'Tigi
String sURL; //File URL `yJpDGh
long nStartPos; //File Snippet Start Position !]7r>NS>
long nEndPos; //File Snippet End Position '"Q;54S**
int nThreadID; //Thread's ID lw0l86^Y
boolean bDownOver = false; //Downing is over IBr?6_\%"4
boolean bStop = false; //Stop identical U#R=y:O?
FileAccessI fileAccessI = null; //File Access interface ]Ow A>fb
7:t+
6!])\Ay
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d4F3!*@(
{ J<BBM.^]
this.sURL = sURL; b_@MoL@A!
this.nStartPos = nStart; dM8`!~#&PI
this.nEndPos = nEnd; w$4fS
nThreadID = id; }7E2,A9_"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GL'zs8AKf
} !},_,J~(|
0|n1O)>J
0dA'f0Uy\X
public void run() sI/Jhw)
{ zl\mBSBx"
while(nStartPos < nEndPos && !bStop) (gZKR2hO
{ }6MHIr=o
}$r/#F/Fn
vL(7|K
try{ J@w Q3#5a
URL url = new URL(sURL); eS9uKb5n(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ` WIv|S
httpConnection.setRequestProperty("User-Agent","NetFox"); }8Tr M0q8
String sProperty = "bytes="+nStartPos+"-"; &wr0HrE\
httpConnection.setRequestProperty("RANGE",sProperty); ^@e4mO
Utility.log(sProperty); s0 hD;`cm
v<N7o8
I5PI;t+
InputStream input = httpConnection.getInputStream(); ZG>I[V'p=
//logResponseHead(httpConnection); E$dPu
VeidB!GyP
cLn&b}8'
byte[] b = new byte[1024]; IY2caXu
int nRead; +T02AS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^=@L(;Y
{ 0@[]l{N
nStartPos += fileAccessI.write(b,0,nRead); oA`'~~!
//if(nThreadID == 1) ys|a ^VnN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <z+5+h|^
} ).e_iE[&
\?A 7{IY
XOK.E&eilj
Utility.log("Thread " + nThreadID + " is over!"); Q[J%
bDownOver = true; F[mL_JU
//nPos = fileAccessI.write (b,0,nRead); e>\[OwF-x
} uuW._$.A>
catch(Exception e){e.printStackTrace ();} `+cc{k
} 0w}OE8uq
} :G\f(2@
n!e4"|4~z
hOjy$Z
//打印回应的头信息 yUcWX bT@
public void logResponseHead(HttpURLConnection con) P 0v&*y3Y
{ y6tzmyg
for(int i=1;;i++) _Vr>/f
{ &|'k)6Rx
String header=con.getHeaderFieldKey(i); qg6283'?
if(header!=null) ousvsP%'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /ghXI"ChI
Utility.log(header+" : "+con.getHeaderField(header)); +HvEiY
else ^6tGj+D9
break; :=!?W^J
} jy#'oadS?
} z)N8#Y~vn
|9cJO@
}_m/3*x_
public void splitterStop() ]Gm"U!h*
{ ^y"5pfSR
bStop = true; @%mJw u
} Oo<L~7B
X,dOF=OJL
iX,|;J|]
} v.Wkz9 w}
seO7/h_a
KLi&TmIB
/* YJi C}.4Q
**FileAccess.java ]/>(C76
*//文件访问(定位，写) iQs7Ly"
package NetFox; #5*|/LD
import java.io.*; @X\-c2=
SJ4[n.tPI
Q@zD'G>
public class FileAccessI implements Serializable{ ;s m )f
ZdQt!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <pzCpF<
RandomAccessFile oSavedFile; /, T@/
long nPos; uR#aO''
@}sxA9a
eiE36+'>b
public FileAccessI() throws IOException 3Q'Q %2
{ Te&F2`vo
this("",0); fHK`u'
} #qqIOjS^w
I6!~(ND7
?86q8E3;&
public FileAccessI(String sName,long nPos) throws IOException A"Q6GM2;Io
{ LDilrG)
oSavedFile = new RandomAccessFile(sName,"rw"); h8#14?
this.nPos = nPos; ft$@':F
oSavedFile.seek(nPos); @,btQ_'X
} oNW5/W2e;
X.^S@3[
R0|dKKzS
public synchronized int write(byte[] b,int nStart,int nLen) h$3o]~t
{ 1yHlBeEC
int n = -1; {*!L[)
try{ V}c3}'_U]
oSavedFile.write(b,nStart,nLen); d~#>.$Uu
n = nLen; wQ!C9Gp3e
} 9p|;Hh:
catch(IOException e) Z{<&2*
{ IpX.ube
e.printStackTrace (); y>4r<YZQ
} ;Ih:$"$!
PtP{_9%Dz
2Fwp\I;
return n; NF9fPAF%;
} [=f(u wY>g
O"%b@$p\L
vRp#bScc
} xw[KP [(
4}C^s\?z
,|:TML
/* `v;9!ReZV
**SiteInfoBean.java ,ddoII
*/ ;h|zNx0
package NetFox; !h\>[O
6k569c{7
v D"4aw
public class SiteInfoBean { RRXnj#<g
cOz8YVR-
yDmNPk/
private String sSiteURL; //Site's URL `XT8}9z!
private String sFilePath; //Saved File's Path ANqWY&f
private String sFileName; //Saved File's Name 5%`fh%
private int nSplitter; //Count of Splited Downloading File =~qQ?;on
.x6c.Y.S
#J4{W84B
public SiteInfoBean() j6Msbq[
{//nSplitter的缺省值为5 #kho[`9
//default value of nSplitter is 5 o|r8x_!+
this("","","",5); gzV&S5A{_
} xLZJ[:gr
kBF.TGT[l
/#WRd}IjK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a| w.G "W
{ W8bh49
sSiteURL= sURL; Vr%>'XN>"
sFilePath = sPath; hDPZj#(c
sFileName = sName; >"Tivc5
this.nSplitter = nSpiltter; -L zx3"
tsGt,]O30
qeM`z
} l:' 0
,q[aV 6kO
\&[Jtv *
public String getSSiteURL() c4\Nuy
{ abs\Ku9
return sSiteURL; H@-txO1`::
} g3fxf(iY(
no~Yet+<"
6A$ Y]u
public void setSSiteURL(String value) jFE1k(2e
{ {DP%=4
sSiteURL = value; c;RL<83:
} YTb/ LeuT
S5%I+G3
3vcKK;qCB
public String getSFilePath() ]x;*Z&
{ =I(F(AE
return sFilePath; yUUg8xbpxF
} |IN{8
IF>dsAAI<
*F4"mr|\
public void setSFilePath(String value) yX`5x^wVw
{ @ OSSqH
sFilePath = value; wWh)yfPh8H
} htgtgW9 ^P
M/Twtq-`H
ON.1'Wk?
public String getSFileName() !L|}/u3v
{ lla?;^,
return sFileName; LtJl\m.th
} bi01]
#L3heb&9
obRYU|T
public void setSFileName(String value) W{)RJ1
{ =qg;K'M5
sFileName = value; ?.*^#>-
} 84X/=l-c=
&"_5?7_N
{jK:hQX
public int getNSplitter() c3L)!]kB
{ @2X{e7+D
return nSplitter; o+}>E31a
} o.o$dg(r!
w6Owfq'v
>14x.c
public void setNSplitter(int nCount) }{oZdO
{ xJNV^u
nSplitter = nCount; @Yu=65h
} >GV(\In
} )qq5WShMJ
NKyKsu
3EVAB0/$
/* F{'lF^Dc
**Utility.java mdNIC
*/ $FJf8u`
package NetFox; X~o6Xkg
ntZl(]l
A.8[FkiNmD
public class Utility { NUQ?QQ
w4<n=k
F5+)=P#
public Utility() 3$~oQC
{ uXm_ pQpF
A0A]#=S
zP`&X:8
} H,Y+n)5
7_G$&
//线程睡眠 5Z<y||=
public static void sleep(int nSecond) E3~Wyfd7
{ NB.s2I7
try{ qhQeQ
Thread.sleep(nSecond); Zr#\>h'c
} &BZjQK
catch(Exception e) UG,<\k&
{ 0rA&Q0
e.printStackTrace (); zHg1K,t:
} qOD:+b
} C25EIIdRb
vMHJgpd&j
//日志 sI OT6L^7
public static void log(String sMsg) X$0&tmum
{ D=^|6}
System.err.println(sMsg); i^Ip+J+[
} kp=wz0#
"BvAiT{u
2zlBrjk;
public static void log(int sMsg) N,0&xg3
{ ,| Zkpn8
System.err.println(sMsg); !zR1CM
} 1:j[p=Q&
} VX+:C(m~
b9L"?{
9l&4mt;+&<
/* I$Ra*r
**TestMethod.java SKdh!*G
*/ c*N>7IF,
package NetFox; XPfheV G
H3Zsm)+:
J};=)xLX;
public class TestMethod { Fs 95^T
;%YAiW8{Xk
(DTXc2)c
public TestMethod() z<jH{AU
{ ///xx/weblogic60b2_win.exe lWRRB&8
try{ F4|U\,g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U^~jB= =]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N_Q\+x}zq
SiteFileFetch fileFetch = new SiteFileFetch(bean); \ 0J&^C
fileFetch.start(); 8Rric[v
} ?Mj@;O9>'
catch(Exception e){e.printStackTrace ();} .ZVADVg\
SMMvRF`7
)ePQN~#K}
} lG/h[
d>-k-X-[
0)HZ5^J
public static void main(String[] args) L^%jR=
{ cd3;uB4\,
new TestMethod(); ZGgM-O1
} L; (J6p]h
} T*bBw
点击下载更多相关资料