http断点续传简单实现（java)

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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)); -|m3=#
} +zMPkbP6
for(int i=0;i<nEndPos.length-1;i++) #!R>`l(S
{ =Z:]%
nEndPos = nStartPos[i+1]; Mc@9ivwL#
} (46'#E z[F
nEndPos[nEndPos.length-1] = nFileLength; $3HqVqF^R
} *XhlIQ
} =){G
0AQ4:KV(Y
"?3=FBp&
//启动子线程 f $Agcy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "i;.>
for(int i=0;i<nStartPos.length;i++) xO )c23Z)]
{ c]|vg=W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n;Oe-+oSC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5Z!$?J4Rl
nStartPos,nEndPos,i); nd8<*ru$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]H n:c'aT
fileSplitterFetch.start(); rS BI'op
} A{zqr^/h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hc|A:v)]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NlEyT9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~{Iw[,MJ
nEndPos = " + nFileLength); CXrOb+
// fileSplitterFetch[nPos.length-1].start(); c6xr[tc%
cpa" ,8
9<_hb1'
//等待子线程结束 +x 3x
//int count = 0; gLv+L]BnhH
//是否结束while循环 |KYl'"5\
boolean breakWhile = false; kzZgNv#G;
o&1mX
{:gx*4}q8
while(!bStop) HqWWWCWal
{ #AGO~#aK
write_nPos(); S!8<|WO^t
Utility.sleep(500); J=3{<Xl
breakWhile = true; 4P3RRS
Pw<?Dw]m
h.vy SwF"j
for(int i=0;i<nStartPos.length;i++) uy<3B>3~.
{ utZI'5i
if(!fileSplitterFetch.bDownOver) ;-u]@35
{ Mgw#4LU
breakWhile = false; 1 7~Pc
break; C|&tdh :g
} uQW)pD{_
} fS4foMI63)
if(breakWhile) q0+N#$g#
break; -NwG' U~
3%)cUkD
`VwG]2 I
//count++; :g|.x
//if(count>4) QPf\lN/$4d
// siteStop(); _;PQt" ]
} HKJCiQ|k
;I*t5{
kc2B_+Y1
System.err.println("文件下载结束！"); 0cHcBxdF
} Eg`~mE+a
catch(Exception e){e.printStackTrace ();} M$EF 8
} QfEJU8/5d
,9ueHE
"QOQ
//获得文件长度 PL=v,NB
public long getFileSize() vb~%u;zrC@
{ ;&j'`tP
int nFileLength = -1; >k"O3Pc@
try{ SdlO]y9E
URL url = new URL(siteInfoBean.getSSiteURL()); B1}i0pV,,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QwhO/
httpConnection.setRequestProperty("User-Agent","NetFox"); |^8ND#x
rd->@s|4mT
En&7e
int responseCode=httpConnection.getResponseCode(); ELwXp|L
if(responseCode>=400) _K#7#qp2
{ (>0`e8v!
processErrorCode(responseCode); KcV"<9rE
return -2; //-2 represent access is error z#Jw?K_
} @TALZk'%
|2^mCL.r
{1)bLG|$
String sHeader; VDnrm*
,.P]5 lE
?/&X_O
for(int i=1;;i++) PJB_"?NTTC
{ 1^$hbRq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LE}`rW3
//Utility.log(in.readLine()); N#M>2b<A/T
sHeader=httpConnection.getHeaderFieldKey(i); EN`JzLjP
if(sHeader!=null) 28^/By:J
{ G%~Vb
if(sHeader.equals("Content-Length")) |gA@$1+}
{ 9q?knMt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IA0vSF:
break; esSj 3E
} TE&E f$h
} rrU(>jA!
else ;*qXjv& K
break; v>K|hH
} g=D]=&H
} M{p6&eg
catch(IOException e){e.printStackTrace ();} R,D/:k'~k
catch(Exception e){e.printStackTrace ();} '~b
Ut~YvWc9
49E| f ^q
Utility.log(nFileLength); {@KLN<
G:b6Wf
x%X3FbF]
return nFileLength; 8i"CU:(
} A&1EOQ=N
eJqx,W5MK]
G--vwvL
//保存下载信息（文件指针位置） e[x,@P`
private void write_nPos() 6'*6tS
{ [5xm>Y&}
try{ gs1
output = new DataOutputStream(new FileOutputStream(tmpFile)); |6-9vU!LK?
output.writeInt(nStartPos.length); 60~*$`
for(int i=0;i<nStartPos.length;i++) |u`YT;`!"-
{ MDa[bQNM
// output.writeLong(nPos); ZOqA8#\
output.writeLong(fileSplitterFetch.nStartPos); CxaI@+
output.writeLong(fileSplitterFetch.nEndPos); 7Z]?a
} =z5=?
output.close(); qX5]\nX&G
} Pq~#SxA~
catch(IOException e){e.printStackTrace ();} ("A45\5
catch(Exception e){e.printStackTrace ();} {!( htg;
} w:B&8I(n}w
{C`M<2W]
suQ`a_zJ
//读取保存的下载信息（文件指针位置） KUX6n(u
private void read_nPos() L' _%zO
{ ,?U(PEO\f
try{ @~{TL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f4<~_ZGr
int nCount = input.readInt(); 7]u_
nStartPos = new long[nCount]; ST#)Fl
nEndPos = new long[nCount]; ,^4"e (
for(int i=0;i<nStartPos.length;i++) b?=r%D->w
{ :fX61S6)
nStartPos = input.readLong(); ce4rhtkV
nEndPos = input.readLong(); q@1A2L\Om
} .))k
input.close(); "nJMS6HJ[
} uR")@Tc
catch(IOException e){e.printStackTrace ();} xg%{p``
catch(Exception e){e.printStackTrace ();} B7A.~'=
} :zC=JvKT
mq<:^
56."&0
private void processErrorCode(int nErrorCode) ^38kxwh
{ 9&kY>M>z0
System.err.println("Error Code : " + nErrorCode); n}%_H4t
} x2~fc
G|?V}pZ
'lC=k7@x
//停止文件下载 ( K-7z
public void siteStop() o}36bi{
{ z4.|N
bStop = true; 8oHIXnK
for(int i=0;i<nStartPos.length;i++) mFpj@=^_G
fileSplitterFetch.splitterStop(); y54RD/`-
oMn'{+(w
LUx'Dm"
} T}p|_)&y
} VKXB)-'L
//负责部分文件的抓取 L(y~ ,Kc
**FileSplitterFetch.java r+]a
*/ Qc9[/4R>
package NetFox; mV7_O//
:'H}b*VWx
-K^(L#G
import java.io.*; muK)Yw[#N
import java.net.*; ;(g"=9e
oPAc6ObOV~
-uAGG?ZER
public class FileSplitterFetch extends Thread { ciHTnC
dg N#"
>hnhV6ss
String sURL; //File URL }&ew}'*9)
long nStartPos; //File Snippet Start Position qqYQ/4Ajw
long nEndPos; //File Snippet End Position ) \cnz
int nThreadID; //Thread's ID }sZy|dd
boolean bDownOver = false; //Downing is over bnp:J|(ld
boolean bStop = false; //Stop identical Sr6iQxE
FileAccessI fileAccessI = null; //File Access interface ;%n(ARZ#
_}`y3"CD7
{yBd{x<>/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -RThd"
{ i[U=-4 J
this.sURL = sURL; cJ,`71xop,
this.nStartPos = nStart; F0'o!A#|(
this.nEndPos = nEnd; sGMnm
nThreadID = id; gcM(K.n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]w8h#p
} S@L%X<Vm
IgF#f%|Q
.}tpEvAw}
public void run() |Pse=_i
{ ijNI6_eU
while(nStartPos < nEndPos && !bStop) %eu_Pr6X
{ H~<wAer,Op
e $5s],,n
+zFEx%3^
try{ RoD9
URL url = new URL(sURL); Im`R2_(]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~r]$(V n
httpConnection.setRequestProperty("User-Agent","NetFox"); >&qaT*_g
String sProperty = "bytes="+nStartPos+"-"; (n{!~'3
httpConnection.setRequestProperty("RANGE",sProperty); /P{'nI
Utility.log(sProperty); 0pe*DbYP5
mc6W"
s[*I210
InputStream input = httpConnection.getInputStream(); F.R0c@&W
//logResponseHead(httpConnection); aOW~! f/M
PPtJ/ }\
du=[r
byte[] b = new byte[1024]; (5^SL Y
int nRead; VS<w:{*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QRY7ck:N
{ &4F iYZ
nStartPos += fileAccessI.write(b,0,nRead); ;xE1#ZT
//if(nThreadID == 1) TP/bPZY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ukXKUYNm8
} 4kLTKm:G
Uv3Fe%>
~!dO2\X+
Utility.log("Thread " + nThreadID + " is over!"); (7PVfS>;
bDownOver = true; E+aE5wmr
//nPos = fileAccessI.write (b,0,nRead); Luh*+l-nO
} y=WCR*N
catch(Exception e){e.printStackTrace ();} cT^x^%
} B\7 80p<
} t4,(W`
cy_zEJjbD
^t)alNGos
//打印回应的头信息 O$&4{h`
public void logResponseHead(HttpURLConnection con) k{C|{m
{ )0@&pEObm
for(int i=1;;i++) w3oe.hWP3N
{ 9O#?r82
String header=con.getHeaderFieldKey(i); 8F`799[p
if(header!=null) }KL( -Ui$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jowR!rqf
Utility.log(header+" : "+con.getHeaderField(header)); & MfnH
else P0szY"}
break; "CWqPcr
} }2_i<4,L
} y +c 3#
Os|F
NIOWjhi[Jn
public void splitterStop() 4}=Z+tDu>
{ X=b]Whuv
bStop = true; rexy*Xv`2p
} GI*2*m!u
gNo}\ lm4V
V_7QWIdiy>
} vJ!<7 l&
*Ry "`"
5},kXXN{+
/* $P~Tt4068
**FileAccess.java 3MFb\s&Fq
*//文件访问(定位，写) SQVyCxcX_
package NetFox; 'x\{sv
import java.io.*; -qndBS
w4p<q68
P&]PJt5
public class FileAccessI implements Serializable{ l7=WO#Pb
5oIgxy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _LSf )
RandomAccessFile oSavedFile; 9l9|w4YJs
long nPos; z}m)u
xu0pY(n^r
O_wRI\!
public FileAccessI() throws IOException ZnYoh/
{ ;;l-E>X0
this("",0); {VrjDj+Xy
} <swYo<?J#
[6t!}q
|#!P!p}
public FileAccessI(String sName,long nPos) throws IOException wNm~H
{ T8rf+B/.L
oSavedFile = new RandomAccessFile(sName,"rw"); g{06d~Y
this.nPos = nPos; }7jg>3ng(
oSavedFile.seek(nPos); %phv<AW
} Nt'u;0
5hbQUF ,Q
F45UO%/P
public synchronized int write(byte[] b,int nStart,int nLen) |CFTOe\q
{ DR6 OR B7
int n = -1; V|8`]QW@
try{ {$mj9?n=v
oSavedFile.write(b,nStart,nLen); i.`RQZ$,/
n = nLen; SLG3u;Ab
} F[SYs/M
catch(IOException e) HJu;4O($
{ j;']L}R
e.printStackTrace (); oUwu:&<Orm
} 0Bpix|mq
6+[7UH~pm^
f}>S"fFI
return n; %,M(-G5j;
} WSW,}tFp"
m^)h/s0A
lE?F Wt
} ,HQaS9vBQ
0vRug|}k#%
aGz<Yip
/* J<{@D9r9<~
**SiteInfoBean.java M _z-~G
*/ `o~9a N
package NetFox; mmj6YQ0a
A;A>Q`JJF
to
public class SiteInfoBean { 5'Fh_TXTD
,4wZ/r> d
:!f1|h
private String sSiteURL; //Site's URL OW12m{
private String sFilePath; //Saved File's Path b}[W[J}`
private String sFileName; //Saved File's Name vK?{Z^J][
private int nSplitter; //Count of Splited Downloading File 'J`%[,@V
`_;VD?")*l
*?`:=
public SiteInfoBean() G*|2qX"o
{//nSplitter的缺省值为5 yU(k;A-
//default value of nSplitter is 5 YrR}55V,
this("","","",5); Uv06f+P(
} @edi6b1W
:h&*<!O2B`
[yF4_UoF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ega< {t
{ :hp=>^$Y
sSiteURL= sURL; /L1qdkG
sFilePath = sPath; .hCOi<wB
sFileName = sName; :B<lDcFKJ
this.nSplitter = nSpiltter; 5"[Qs|VjA6
%@{);5[
DaW_-:@s
} UUx0#D/U0C
`q 4%
<o_H]c->
public String getSSiteURL() @Kd lX>i
{ Cp_YIcnEJ
return sSiteURL; @GYM4T
} :LL>C)(f
TWC^M{e
^zv28Wq>
public void setSSiteURL(String value) Pv`^#BX'
{ a"{tqNc
sSiteURL = value; ?hS n)
} m#'2 3
W)F2X0D>
JeJc(e
public String getSFilePath() 7K`A2
{ L44-: 3
return sFilePath; a<[@p
} 1@H3!V4
MdWT[
:CN,I!:
public void setSFilePath(String value) hIw<gb4J%
{ qPpC)6-Q
sFilePath = value; j0k"iv
} AR?J[e
Nvs8t%
;fhFv&`mE
public String getSFileName() *N$#cz
{ tLpDIA_8
return sFileName; 4 ~17s`+
} ejwFQ'wTx
67Ai.3dR
m?_S&/+*
public void setSFileName(String value) o_<o8!]l"
{ #Vanw!
sFileName = value; v.+-)RLQg
} 74%,v|
~_SV`io
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public int getNSplitter() S5'BXE,
{ #`/KF_a3\>
return nSplitter; 5isejR{r
} 7[55
Ku_`F2Q
77OH.E|$
public void setNSplitter(int nCount) ]OHzE]Q
{ !h2ZrT9 _
nSplitter = nCount; #zXkg[J6d
} =%|S$J
} 5-}4jwk
Bya!pzbpr
I`2hxLwh+
/* 8@!/%"Kt2
**Utility.java b:>(U.
*/ z@$7T:H>
package NetFox; 7vV3"uns
|-I[{"6q$@
Y*0%lq({H
public class Utility { B5!$5Qc
4)iSz>
:t]YPt
public Utility() -ny[Lh^b
{ jR\T\r4
:a3Pnq$]E
5A/G?
} }@}jwi)l
y1/$dn
//线程睡眠 A[Juv]X
public static void sleep(int nSecond) p,@_A'
{ u Y/Q]NT
try{ &`<j!xlG
Thread.sleep(nSecond); 8(D>ws$
} y`=A$>A
catch(Exception e) yjpV71!M
{ ?K{CjwE.M
e.printStackTrace (); ycRy!0l
} dV8mI,h
} qr(SAIX"
<O>r e3s
//日志 9>qR6k?
public static void log(String sMsg) waW2$9O
{ A5+vzu^
System.err.println(sMsg); z:|4S@9
} .wx;!9
zO2Z\E'%.
v?)JM+
public static void log(int sMsg) bQb>S<PT
{ |Z$heYP:w
System.err.println(sMsg); JMpjiB,A}
} +%8c8]2
} $)mE"4FE
8\`]T%h
4)-LlYS_d<
/* ;p/RS#
**TestMethod.java G1vWHa7n;f
*/ 91r#lDR
package NetFox; myFjw@
Z= dEk`
^x4I
public class TestMethod { !Z,h5u\.w
m ,)4k&d
"kz``6C
public TestMethod() E:(flW=
{ ///xx/weblogic60b2_win.exe ^:\|6`{n
try{ G#8HY VF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qn6Y(@<[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2md1GWyP
SiteFileFetch fileFetch = new SiteFileFetch(bean); D(s[=$zua
fileFetch.start(); !9k)hP
} ]&qujH^Dd*
catch(Exception e){e.printStackTrace ();} 2r"-X
r@H<@Vuc
ITRv^IlF
} iQZgs@
fnG&29x
UC;_}>
public static void main(String[] args) b"t!nfgo
{ $VhUZGuG>
new TestMethod(); sYiegX`1c
} }?^5\otu
} R>To L
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