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)); zyTeF~_
} 4@- 'p
for(int i=0;i<nEndPos.length-1;i++) 0@k)Cz[0;
{ :@mb.'%*!
nEndPos = nStartPos[i+1]; cyL"?vR*<
} R^4JM,v9x`
nEndPos[nEndPos.length-1] = nFileLength; }Ndknut,
} #!qa#.Yi
} Xgou7x<
3w6}%=)$8
F$X"?fj
//启动子线程 {FNmYneh?6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4-1=1)c*
for(int i=0;i<nStartPos.length;i++) +G)L8{FY(
{ hX;JMQ915
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e'Njl?>3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5o-WA1
nStartPos,nEndPos,i); 7,X5]U&A<x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s|FfBG
fileSplitterFetch.start(); Wb4+U;C^!'
} .'aW~WR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XnR9/t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /x\{cHAt8J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UDl[
nEndPos = " + nFileLength); ,ELbm
// fileSplitterFetch[nPos.length-1].start(); \iVb;7r)9:
vr/*z euA
oK\{#<gCZ
//等待子线程结束 ai0am
//int count = 0; Q*&k6A"jx
//是否结束while循环 3 vr T`
boolean breakWhile = false; W~b->F
f-$%Ck$%,
`3GYV|LeQ
while(!bStop) 3HCH-?U5
{ <u`m4w
write_nPos(); Q0l[1;$#
Utility.sleep(500); {{N*/E^
breakWhile = true; J%r$jpd'
3M~*4
J?DJA2o
for(int i=0;i<nStartPos.length;i++) 4TX~]tEyky
{ "0Ca;hSLM2
if(!fileSplitterFetch.bDownOver) IHC {2 ^
{ ?Pbh&!
breakWhile = false; `?P)RS30
break; m}`!FaB #
} nz+k ,
} nymro[@O~
if(breakWhile) N#C,q&;
break; 'qoDFR\v
4+?d0
tg5G`P5PJ
//count++; ~IQ3B$4H&
//if(count>4) {XR3L'X
// siteStop(); NW?.Ge.!P
} xQA6!j
zw,( kv
Xlg0u.
System.err.println("文件下载结束！"); >_esLsPWh]
} "Zr+>a
catch(Exception e){e.printStackTrace ();} Z@f4=
} ,]FcWx \u
U?/C>g%/PI
)b\89F
//获得文件长度 e:`d)GE
public long getFileSize() #"&<^
{ 0[L)`7
int nFileLength = -1; Wks?9)Is
try{ LKX; ^
URL url = new URL(siteInfoBean.getSSiteURL()); 5-[bdI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nNj<!}HvV
httpConnection.setRequestProperty("User-Agent","NetFox"); *gGL5<%T:
VelR8tjP
ais@|s;
int responseCode=httpConnection.getResponseCode(); crvq]J5
if(responseCode>=400) <?h,;]U
{ dAba'|Y
processErrorCode(responseCode); ,2>nr goM
return -2; //-2 represent access is error 1[4 2f#
} e]5 n4"]D)
E=3UaYr
%Bxp !Bj
String sHeader; D2N<a=#
5oOF|IYi
jVdRy{MH
for(int i=1;;i++) ~Y)h[
{ t?l0L1;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ))9w)A@
//Utility.log(in.readLine()); JnodDH ?
sHeader=httpConnection.getHeaderFieldKey(i); <&47W
if(sHeader!=null) <0sT
{ GI.=\s
if(sHeader.equals("Content-Length")) B QxU~s
{ 3{/[gX9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ))NiX^)8^
break; SJ0IEPk
} G_1`NyI
} hf('4^
else V(#z{!
break; P70]Ju
} .S{>?2
} oj$^87KX
catch(IOException e){e.printStackTrace ();} IVY{N/ 3|
catch(Exception e){e.printStackTrace ();} 3q}fDM(@J
rb_FBa%
zt3y5'Nk
Utility.log(nFileLength); 1w~@'ZyU
7c8A|E0\mF
mN^/
return nFileLength; #)BbW40f6
} ^.?5!9U
?7|6jTIs
u6#FG9W7
//保存下载信息（文件指针位置） hW Va4
private void write_nPos() P(|+1$#[
{ 5&Vp(A[m[
try{ Et0[HotO
output = new DataOutputStream(new FileOutputStream(tmpFile)); n97pxD_74
output.writeInt(nStartPos.length); -F338J+J24
for(int i=0;i<nStartPos.length;i++) ]>_Ie?L)<
{ 3*<?'O7I0
// output.writeLong(nPos); =" Sb>_
output.writeLong(fileSplitterFetch.nStartPos); |A/)b78'u
output.writeLong(fileSplitterFetch.nEndPos); 7Z7e}| \W
} 9vL n#_
output.close(); +r<d z
} /&jh10}H
catch(IOException e){e.printStackTrace ();} bw[s<z|LKA
catch(Exception e){e.printStackTrace ();} D *Hy 2eZ.
} mh7JPbX|
rAwuWM@BIg
=ICakh!TO
//读取保存的下载信息（文件指针位置） d) i64"
private void read_nPos() Jv[c?6He
{ l2|[
try{ 'jr[ ?WQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WJA0 `<~
int nCount = input.readInt(); -qW[.B
nStartPos = new long[nCount]; b,r{wrLe)
nEndPos = new long[nCount]; PN"s^]4
for(int i=0;i<nStartPos.length;i++) 1RM@~I$0
{ h,!`2_&UQ
nStartPos = input.readLong(); </B<=tc
nEndPos = input.readLong(); At$[&%}
} XcH_Y
input.close(); zho$g9*
} 4apy{W
catch(IOException e){e.printStackTrace ();} D.:6X'hp
catch(Exception e){e.printStackTrace ();} kh5VuXpe
} NG\g_^.M
)wdTs>W7
s+a} _a:
private void processErrorCode(int nErrorCode) 1/J3 9Y~+
{ X :wfmb
System.err.println("Error Code : " + nErrorCode); 6t!PHA
} chs] ,7R
lFT` WO
qC:QY6g$N
//停止文件下载 d,+a}eTP'
public void siteStop() 5u=$m^@{
{ nA4PY]
bStop = true; [#mRlL0yk
for(int i=0;i<nStartPos.length;i++) AdGDs+at,
fileSplitterFetch.splitterStop(); :JD*uu
sn-P&"q
!E.CpfaC
} b-Xc6f
} /]>8V'e\
//负责部分文件的抓取 F`8B PWUY
**FileSplitterFetch.java E=$li
*/ %k=c9ll@:
package NetFox; >p?Vv0*
hj+iB,8
7M,(!*b
import java.io.*; }[mLtv%&
import java.net.*; 9?38/2kX4
^_5t5>
}BN!Xa
public class FileSplitterFetch extends Thread { C.N#y`g
:/XWk %
q.s'z}
String sURL; //File URL 7N4)T'B
long nStartPos; //File Snippet Start Position Boj#r ,x
long nEndPos; //File Snippet End Position aNDpCpy
int nThreadID; //Thread's ID /|LQ?n
boolean bDownOver = false; //Downing is over h\lyt(.s
boolean bStop = false; //Stop identical :D:Y-cG*n<
FileAccessI fileAccessI = null; //File Access interface FXG,DJ:
=x3T+)qCNX
%}[/lIxaE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException # ~(lY}
{ %@MO5#)NI
this.sURL = sURL; f~P~%
this.nStartPos = nStart; a%*W( 4=Y
this.nEndPos = nEnd; 0u?VnN<
nThreadID = id; rk8Cea
fileAccessI = new FileAccessI(sName,nStartPos);//定位 awU&{<,=g
} oZ\zi> Y,
Vu5Djx'
DDBf89$\
public void run() %G/(7l[W
{ pF<KhE*V
while(nStartPos < nEndPos && !bStop) `dJ?j[P,p
{ S5/p3;O\c
qlm7eS"sy
q_86nvB<
try{ oCSJ<+[(C
URL url = new URL(sURL); &6&$vF65c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l&{+3aC:
httpConnection.setRequestProperty("User-Agent","NetFox"); @B9O*x+n:
String sProperty = "bytes="+nStartPos+"-"; Pj^O8
httpConnection.setRequestProperty("RANGE",sProperty); ~9Cw5rwH<;
Utility.log(sProperty); on.m '-s
:V~ AjV
-'rb+<v
InputStream input = httpConnection.getInputStream(); *0/%R{+S
//logResponseHead(httpConnection); +ux170Cd3
rYO~/N
vl>_;}W7
byte[] b = new byte[1024]; ,% *Jm
int nRead; iD)P6"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &I7T?
{ >uR;^B5m
nStartPos += fileAccessI.write(b,0,nRead); ZsN3 MbY
//if(nThreadID == 1) 6ANAoWg*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $D;-;5[-/r
} 8I<LZ{a10
L8?;A9pc()
|vY|jaV}
Utility.log("Thread " + nThreadID + " is over!"); \me-#: Gu
bDownOver = true; I>:.fHvUC
//nPos = fileAccessI.write (b,0,nRead); >K*TgG6!X
} [E;~Y_l
catch(Exception e){e.printStackTrace ();} !m?W+z~J
} sfR0wEqI
} J~lKN <w
3Y=uBl
(|sqN8SbA
//打印回应的头信息 MrhJk
public void logResponseHead(HttpURLConnection con) &24>9
{ 4IXa[xAm
for(int i=1;;i++) $j&2bO5M
{ lB(P+yY,/'
String header=con.getHeaderFieldKey(i); I 8 Ls_$[
if(header!=null) C8$/z>tQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G$1gk^G's
Utility.log(header+" : "+con.getHeaderField(header)); [-2Tj)P C
else Y*YV/E.
break; S<>u
} @pV&{Vp
} VV"1IR
Eg0qY\'
=z9FjK
public void splitterStop() M9/J!s
{ 3`{[T17
bStop = true; 5mg] su&#
} 4n/CSAT1
7F8>w 7Y]
6mC% zXR5
} v,Yz\onB^
aKw7m={
3/*<i
/* kx07Ium
**FileAccess.java o&kgRv[
*//文件访问(定位，写) kXW$[R
package NetFox; bf$4Z: Y
import java.io.*; Pql;5 ~/
;"+]bne~
W(jP??up
public class FileAccessI implements Serializable{ tkf^sGgNO
7_ao?}g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7hl,dtn7
RandomAccessFile oSavedFile; S3&lkN5
long nPos; i`EG80\[Z
k>!A~gfP~
(zhi/>suG
public FileAccessI() throws IOException {KM5pK?,BJ
{ g:fzf>oQ>p
this("",0); Rx.dM_S
} @1+({u#B
$s!2D"wl n
ZR@PqS+O/
public FileAccessI(String sName,long nPos) throws IOException /PgcW
{ dS~#Lzm
oSavedFile = new RandomAccessFile(sName,"rw"); qb>mUS
this.nPos = nPos; Oh/2$72
oSavedFile.seek(nPos); c~{)vL0K
} w$[ck=
R^tDL
<hmRr
public synchronized int write(byte[] b,int nStart,int nLen) Qj(|uGqm3
{ ljw>[wNv
int n = -1; i2m+s;
try{ <ly.l]g
oSavedFile.write(b,nStart,nLen); ,-_\Y hY>
n = nLen; VXIB9 /*i
} -+Ab[
catch(IOException e) fv?vfI+m
{ a^.5cJ$]
e.printStackTrace (); e$=0.GWT
} U8icP+Y
@/0-`Y@?
FvV:$V|
return n; K9+%rqC.|`
} !%Qm{R
Uh8c!CA8:\
WR@TH bU
} !(-S?*64l
9M!J7 W
1"P^!N
/* B kWoK/f4
**SiteInfoBean.java CJ#1j>
*/ 3F|#nq
package NetFox; k\`~v$R3
P*zOt]T
sqP (1|9
public class SiteInfoBean { ~Bs=[TNd[
mu# a
@O Rk
private String sSiteURL; //Site's URL Rw#4 |&
private String sFilePath; //Saved File's Path +4*jO5EZ
private String sFileName; //Saved File's Name Jx_BjkF
private int nSplitter; //Count of Splited Downloading File AQa;D2B$
pQf5s7
tNbZ{=I>
public SiteInfoBean() O0Sk?uJ<
{//nSplitter的缺省值为5 N#"(
//default value of nSplitter is 5 YqSkz|o}m
this("","","",5); ;R8pVj!1f
} ofIw7D*h
)S2GPn7
0281"aO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mcFJ__3MAV
{ z),@YJU"z
sSiteURL= sURL; 0.}WZAYy~
sFilePath = sPath; F2#s^4Ii
sFileName = sName; JXA!l?%
this.nSplitter = nSpiltter; B8sc;Z.
! >l)*jN8
#`(-Oj2hH
} 27q=~R}
F.[E;gOTo
b6y/o48
public String getSSiteURL() ?z$^4u3
{ "fTW2D74
return sSiteURL; OX!<{9o
} 0v/}W(
PA_54a9/<
qZz?i
public void setSSiteURL(String value) 7g&"clRGO
{ VA^yv1We
sSiteURL = value; c&AJFED]<
} dnW#"
?f\ ~:Gm/
48 n5Y~YS
public String getSFilePath() ap y#8]
{ GjD^\d/
return sFilePath; B{ptP4As-
} ljw(cUM
}> pNf
/ 80Q
public void setSFilePath(String value) 8'}D/4MUr
{ Ga M:/.
sFilePath = value; j{?ogFfi
} td"D&1eQ@
p|f5w"QcH
Y_SB3 $])
public String getSFileName() <<5x"W(,
{ gf\F%VmSN
return sFileName; ^^FqN;
} dbG5Cf#K\
ys~oJb~
io1hUZ
public void setSFileName(String value) s=BJ7iU_68
{ a2!;$B%
sFileName = value; s`63 y&Z[
} r]<?,xx[
}F<=
)@,zG(t5;
public int getNSplitter() V[RsSZx =
{ KW 78J~u+
return nSplitter; L55VS:'
} =(cfo_B@K
6Ex16
EjDr
public void setNSplitter(int nCount) ?Tr\r1s]
{ %~$coZY^
nSplitter = nCount; OB5t+_s
} XKQ\Ts2<k
} 4Y `=`{Q
W#sCvI@
=`W#R
/* I/`\>Hk
**Utility.java $z[r(a^a
*/ *Al`QEW
package NetFox; g* DBW,
3U!#rz"
/4wPMAlb
public class Utility { l37) Q
H5X.CcI&}
7S.E,\Tws
public Utility() m(rd\3d
{ eH' J
x$+g/7*
<S@XK%
} j3&tXZ;F
sB+ B,DF
//线程睡眠 RQQ\y`h`
public static void sleep(int nSecond) O&@pi-=o
{ -kkpEw\
try{ yDmx)^En
Thread.sleep(nSecond); j~C-T%kYa
} /P koqA,
catch(Exception e) a=&{B'^G
{ 1%Su~Z"W>
e.printStackTrace (); i{2ny$55h
} Gq0Q}[53
} ,f)#&}x*2+
TJ+,G4z
//日志 >^TcO
public static void log(String sMsg) {}DoRpq=
{ +V;@)-
System.err.println(sMsg); }+dDGFk
} [iGL~RiXtn
<&MY/vV
MYMg/>f[
public static void log(int sMsg) :=e"D;5
{ _,bDv`>Ra
System.err.println(sMsg); C<yjGtVD
} G^&P'*
} klxNGxWAX
v)s; wD
Gzkvj:(V
/* cTu"Tu\Qw
**TestMethod.java 45U!\mG
*/ ? uu,w
package NetFox; AZf$XHP2
$c1xh.
=.\PG[
public class TestMethod { ?*dt JL
o3,}X@p
\SyG#.$
public TestMethod() o%)38T*n3
{ ///xx/weblogic60b2_win.exe [I2vg<my
try{ YLehY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;Yu|LaI\<m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s~g0VNu Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); R@A"U[*
fileFetch.start(); GFfZ TA
} 2 i97
catch(Exception e){e.printStackTrace ();} <}('w/
*RJiHcII
~jDf,a2
} 5h@5.-}
&at>sQ'
4H_QQ6
public static void main(String[] args) f <pJ_
{ ?G<.W[3
new TestMethod(); [iUy_ C=qp
} 7QM1E(cMg
} Vl`!6.F3
点击下载更多相关资料