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)); g m],
} s:cS 9A8
for(int i=0;i<nEndPos.length-1;i++) .?S#DS )
{ sa+:c{
nEndPos = nStartPos[i+1]; AJ:@c7:eS
} $b$r,mc
nEndPos[nEndPos.length-1] = nFileLength; #D+Fq^="P
} 6M$.gX G.
} Qq]UEI `Go
bTHa;* `
^ I,1kl~i
//启动子线程 &TWO/F+Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5 |C;]pq
for(int i=0;i<nStartPos.length;i++) n]coqJ
{ %_SE$>v^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?-\KVha
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8N-~.p
nStartPos,nEndPos,i); o<P%|>qX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L +.K}w
fileSplitterFetch.start(); G68N@g
} h/(9AO}t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AD?^.<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dGh<R|U3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5'V'~Q%
nEndPos = " + nFileLength); r?/>t1Z
// fileSplitterFetch[nPos.length-1].start(); N??<3j+Iu
2#W%--
a9jY^E'|n
//等待子线程结束 p7H*Ff`
//int count = 0; b<.+WkO
//是否结束while循环 ^ad> (W
boolean breakWhile = false; 6o A0a\G'
9R;s;2$.
zLXtj-
while(!bStop) 7P|(j<JX6'
{ S8,+6+_7
write_nPos(); `O}. .N]g
Utility.sleep(500); <6L$:vT_
breakWhile = true; N{p2@_fnB
<O\z`aA'q
FT(EH
for(int i=0;i<nStartPos.length;i++) [V jd)%
{ y'yaCf
if(!fileSplitterFetch.bDownOver) 4?yc/F=kI
{ ;-]f4O8
breakWhile = false; ^2^ptQj
break; q9WSQ$:z8
} g\*gHHa
} P<4jY?.
if(breakWhile) R?&S]?H
break; 6/#= dv
[Q 2t,tQx
Vj?.'(
//count++; Qn*c<:
//if(count>4) T.`%1S
// siteStop(); U5Ho? `<
} !^"hYp`
O&w$
$yFur[97C
System.err.println("文件下载结束！"); MzG(+B
} :Dr& {3>
catch(Exception e){e.printStackTrace ();} HZK0Ldf
} ]-PF?8
h0^V!.-5
caj)
//获得文件长度 nW drVT$
public long getFileSize() \GvVs
{ z~VA#8>
int nFileLength = -1; -O_UpjR;
try{ [#9ij3vxd
URL url = new URL(siteInfoBean.getSSiteURL()); C,IN+@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #JLDj(a?
httpConnection.setRequestProperty("User-Agent","NetFox"); 9C4l@jrF
r 2
^c(PZ,/#JB
int responseCode=httpConnection.getResponseCode(); G0(c@FBK
if(responseCode>=400) E$ngmm[
{ g3Xz-
processErrorCode(responseCode); <hK$Cf_
return -2; //-2 represent access is error k Lv_P[I
} |t]9RC.;7
ToMX7xz6
!<YRocQY
String sHeader; quKD\hL$
BO9Z"|"
Zi[)(agAT
for(int i=1;;i++) mJsYY,b8
{ Iiy:<c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ynDx'Q*N'
//Utility.log(in.readLine()); M5x!84
sHeader=httpConnection.getHeaderFieldKey(i); pz$$K?
if(sHeader!=null) _N-7H\hF
{ v;RQVH;,
if(sHeader.equals("Content-Length")) Zgg7pL)#c
{ !gk\h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Fb``&-Qm:
break; 0zTv'L
} <7jb4n<
} yav)mO~QU6
else tm|lqa
break; T*{zL
} "FXS;Jf
} tAC,'im:*
catch(IOException e){e.printStackTrace ();} FI/YJ@21
catch(Exception e){e.printStackTrace ();} zhCI+u4/qz
U1"t|KW8
@B'Mu:|f
Utility.log(nFileLength); V!opnLatYS
-DuiK:mp
*g,?13Q_
return nFileLength; P5d@-l%}
} :O!G{./(_
`-/l$A} U
(jm.vL&5j
//保存下载信息（文件指针位置） ILO+=xU
private void write_nPos() SQ Fey~
{ n47=eKd70
try{ <eh(~
output = new DataOutputStream(new FileOutputStream(tmpFile)); xXx`a\i
output.writeInt(nStartPos.length); 8;!Eqyt
for(int i=0;i<nStartPos.length;i++) jo(Q`oxm!>
{ !}PFiT^
// output.writeLong(nPos); GY",AL8f
output.writeLong(fileSplitterFetch.nStartPos); kIfb!
output.writeLong(fileSplitterFetch.nEndPos); >C-_Zv<!T\
} jF3!}*7,
output.close(); 8x9kF]=
} )>Q 2G/@
catch(IOException e){e.printStackTrace ();} o5D"<-=>
catch(Exception e){e.printStackTrace ();} H4m6H)KOG
} 23f[i<4e
PPqTmx5S
j^ _I{
//读取保存的下载信息（文件指针位置） 3N bn|_`(
private void read_nPos() 4y1>!~f
{ 7>zKW?
try{ @*uX[)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9V],X=y~
int nCount = input.readInt(); 5j{@2]i
nStartPos = new long[nCount]; fD~!t 8J
nEndPos = new long[nCount]; 38m%ifh)
for(int i=0;i<nStartPos.length;i++) a`-hLX)~Z
{ ];I|_fXo%
nStartPos = input.readLong(); 1SFKP$^
nEndPos = input.readLong(); Ij#a
} 1:Yt2]
input.close(); y\_S11{v
} N#u8{\|8]
catch(IOException e){e.printStackTrace ();} l'W+^
catch(Exception e){e.printStackTrace ();} #c^Q<&B
} [;=WnG
0`!Q-G7
baNfS
private void processErrorCode(int nErrorCode) ZW?7g+P
{ UTTC:=F+
System.err.println("Error Code : " + nErrorCode); AIm$in`P
} jOb[h=B"
& .?HuK
BY0|exW
//停止文件下载 YSV,q@I&1
public void siteStop() )KqR8UO
{ X}*o[;2G
bStop = true; mU=6"A0 U
for(int i=0;i<nStartPos.length;i++) |\a:]SlH
fileSplitterFetch.splitterStop(); Ib2@Wi
KCk?)Qv
s3M84wz
} x ctU.)p
} gFT~\3jp=
//负责部分文件的抓取 t%U[\\ic
**FileSplitterFetch.java CJ?gjV6
*/ m"G N^V7
package NetFox; PEBFN
q~J oGTv
Z% ;4Ed
import java.io.*; >'6GcnEb4.
import java.net.*; Nr"N\yOA/
-m160k3
V./w06;0
public class FileSplitterFetch extends Thread { {F:v$ K
y"\,%.
w"v'dU^
String sURL; //File URL -WUYE
long nStartPos; //File Snippet Start Position ]VWfdG
long nEndPos; //File Snippet End Position u-[t~-(a
int nThreadID; //Thread's ID QWHy=(!
boolean bDownOver = false; //Downing is over Q==v!"Gi|
boolean bStop = false; //Stop identical jAK{<7v4U
FileAccessI fileAccessI = null; //File Access interface eFSC^
AD@PNM
u7"VeTz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r%l%yCH
{ mY`]33??v
this.sURL = sURL; cIr1"5POXK
this.nStartPos = nStart; wz+5 8(
this.nEndPos = nEnd; 0sd-s~;
nThreadID = id; +V9B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sdf%
} *kQCW#y0
~B!O~nvdQ
DvX3/z#T
public void run() Iv(Qa6(
{ )E:,V~< 8
while(nStartPos < nEndPos && !bStop) Iz)hz9k
{ P/pjy
QP%kL*=8
6!B^xm.R@
try{ "PyWo
URL url = new URL(sURL); @%<?GNSO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yvz?4m"_yB
httpConnection.setRequestProperty("User-Agent","NetFox"); nnE_OK!}T
String sProperty = "bytes="+nStartPos+"-"; FxfL+}?Q
httpConnection.setRequestProperty("RANGE",sProperty); (.1 rtj
Utility.log(sProperty); Q)S>VDLA
`xUG|
umjhG6
InputStream input = httpConnection.getInputStream(); y|.fR>5
//logResponseHead(httpConnection); v'@b.R,
*sw-eyn(
ns#~}2"d
byte[] b = new byte[1024]; _Dj<Eu_
int nRead; zq;DIWPIoJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &G/|lv>j
{ ole|J
nStartPos += fileAccessI.write(b,0,nRead); y?#9>S >:\
//if(nThreadID == 1) HmExfW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A/"}Y1#qX\
} vWl[l -E
,?k%jcR
5#0e={X
Utility.log("Thread " + nThreadID + " is over!"); Ka]@[R6e
bDownOver = true; xP/OsaxN
//nPos = fileAccessI.write (b,0,nRead); sz/*w7
} @8nLQh^
catch(Exception e){e.printStackTrace ();} qWO]s=V!
} wn+j39y?ZY
} 's[BK/
t'R':+0Vf
t<sNc8x
//打印回应的头信息 3@)obb
public void logResponseHead(HttpURLConnection con) e40udLH~x
{ @Y UY9+D&
for(int i=1;;i++) ,;.B4
{ EqnpMHF
String header=con.getHeaderFieldKey(i); {pDTy7!Hs
if(header!=null) UP;Q=t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A XBkJ'jd
Utility.log(header+" : "+con.getHeaderField(header)); hOPe^e"
else d(fPECv(
break; gF[6c`-s
} M!gBmQZ1
} hr$Sa
?j/kOD0
u 1ZJHry
public void splitterStop() QqtC`H\
{ Hz?!BV0
bStop = true; >z=Ou<,
} Zx+cvQ
rH_Jh}Y
f.oP
} {l2N&
QCOLC2I
o]Wz6L
/* (kIz
**FileAccess.java pI7Ssvi^
*//文件访问(定位，写) u7;`4P:o@
package NetFox; }:`5,b%Y_
import java.io.*; V+lRi"m?|
w[(n>
NZLXN
public class FileAccessI implements Serializable{ Ly9Q}dL
3Y z]8`C
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5W+{U8\
RandomAccessFile oSavedFile; :l+_ja&o
long nPos; z%V*K
DVI7]+=nV
ITyzs4"VV
public FileAccessI() throws IOException !?nu?
{ g96T*T
this("",0); :peqr!I+K
} naz:A
2;G98H
P,i"&9 8
public FileAccessI(String sName,long nPos) throws IOException G0}Dq MTi
{ eC~jgB
oSavedFile = new RandomAccessFile(sName,"rw"); U98_M)-%&
this.nPos = nPos; ->\N_|_
oSavedFile.seek(nPos); P5xI
} q IM
Z>F@nTzb>
.o}%~g<d
public synchronized int write(byte[] b,int nStart,int nLen) %[wTz$S"
{ o{V#f_o
int n = -1; =7 VCtd/
try{ :NuR>~
oSavedFile.write(b,nStart,nLen); d.`&0
n = nLen; HsnG4OE
} 3DW3LYo{
catch(IOException e) *g1L$FBG
{ dK.R[aQ
e.printStackTrace (); 6xarYh(
} iJ)0Y~
&<Mt=(qY1
>uTPjR[
return n; [Tb\woU
} 3jF|Ic
-#aZF2z
'M8aW!~
} Wr5Q5s)c
hK(tPl$
vU!8`x)
/* :.$"kXm^
**SiteInfoBean.java ?; [ T
*/ 5`~mqqR5
package NetFox; ?E<c[*F05
*69c-`o
R}r~p?(M
public class SiteInfoBean { 7^MX l
d+6]u_J
;i\C]*
private String sSiteURL; //Site's URL )~V}oKk0t
private String sFilePath; //Saved File's Path 5Z{_m;I.
private String sFileName; //Saved File's Name 4T`&Sl
private int nSplitter; //Count of Splited Downloading File B'}"AC"
+8AvTSgX%
*Y%Jl o
public SiteInfoBean() ~*}$>@f{[X
{//nSplitter的缺省值为5 WPo:^BD
//default value of nSplitter is 5 =&7@<vBpy
this("","","",5); /^:2<y8Ha
} Q[PK`*2)
-[DWM2C$K4
@2 =z}S3O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \9)#l#m
{ }>}1oUCi
sSiteURL= sURL; CISO<z0
sFilePath = sPath; *N F$1
sFileName = sName; 3qi_]*dD
this.nSplitter = nSpiltter; 0xCz'mJ
q8xd*--#
hj!+HHYSk
} c@R; /m:R
\a))
uZIJoT
public String getSSiteURL() _BS 9GB
{ !msNEE@[
return sSiteURL; {%b }Z2
} Jdj?I'XtY
|QMA@Mx
oM,- VUr
public void setSSiteURL(String value) 2z_2.0/3
{ 3c#s|qW
sSiteURL = value; cin2>3Z$
} |g-b8+.=]
e1/sqXWo
%8mm Hh
public String getSFilePath() +E5=$`
{ h*w6/ZL1
return sFilePath; ? \m3~6y
} zO~9zlik
>7b)y
ZFvyL8o
public void setSFilePath(String value) mR+Jws'
{ 9+qOP>m
sFilePath = value; >jx.R
} gR Nv-^
8SC%O\,
"aq'R(/`c
public String getSFileName() p&N#_dmlH
{ ".U^ifF
return sFileName; riCV&0"n
} WE6\dhJ<
}Ln@R~[
,gx)w^WTm
public void setSFileName(String value) 3[IJhR[
{ #0"~G][#
sFileName = value; +(?>-3_z
} UBZ9A
>#(n"RCHf
!HK^AwNY
public int getNSplitter() u[oUCTY
{ h#qN+qt}
return nSplitter; OqUr9?+
} "y;bsZBd"
F{m{d?:OA
1||+6bRP
public void setNSplitter(int nCount) z[nS$]u
{ E D"!n-Hq
nSplitter = nCount; "Fnq>iR-
} }|wv]U~
} :c.JhE3D
6'C2SihYp
Y[ zZw~yx
/* V[;M&=,"
**Utility.java y\c"b-lQX
*/ ,Zf 9RM
package NetFox; o[\HOe~;
/rc%O*R
1(#;&:$`i
public class Utility { d8o53a]
-db75=
M+P$/Wk
public Utility() ^%>kO,
{ mD58T2Z
{~Tg7<\L
w:i:~f .
} 1wj:aD?g
If-_?wZe
//线程睡眠 Uh6 '$0
public static void sleep(int nSecond) 1B=>_3_
{ ,*svtw:2')
try{ !Ng=Yk>3
Thread.sleep(nSecond); ~P*4V]L^
} /t%u"dP"T~
catch(Exception e) O9M{ ).
{ 0s#Kp49-
e.printStackTrace (); MGpt}|t-
} ;#/@+4@a&
} G$M9=@Ug
'lz"2@4{
//日志 0(TTw(;
public static void log(String sMsg) RFaSwf,5n
{ Cby;?F6w
System.err.println(sMsg); B%s7bS
} s1N?/>lmB
t= #&fSR
=EP13J
public static void log(int sMsg) 9xI GV!
{ zYER
System.err.println(sMsg); lSwcL
} ,:Z^$
} &53]sFZ
3VO2,PCZ
G6 0S|d
/* YwEpy(}hJm
**TestMethod.java fxcc<h4
*/ yay<GP?
package NetFox; YZf6|
&[vw 0N-
(2ot5x}`j
public class TestMethod { Sjj>#}U
=8Jfgq9E
M~e0lg8
public TestMethod() :M3oUE{
{ ///xx/weblogic60b2_win.exe thlY0XCq,%
try{ ;|T!#@j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &)d$t'7p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VosZJv=
SiteFileFetch fileFetch = new SiteFileFetch(bean); f|7\DeY9U
fileFetch.start(); #N(= 3Cj
} 9m2, qr|
catch(Exception e){e.printStackTrace ();} M9\#Aq&\i
}|OaL*|u
'@|_OmcY
} 1$/MrPT(b
&F *'B|n
82{&# Vc
public static void main(String[] args) 5|0,X<&
{ MM_k ]-7
new TestMethod(); C*=Xk/0
} _9 .(a
} r|Z3$J{^"
点击下载更多相关资料