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)); !Z}d^$
} 45qSt2
for(int i=0;i<nEndPos.length-1;i++) Nr(t5TP^
{ Rn4Bl8z'>
nEndPos = nStartPos[i+1]; 2BGS$$pP
} }j_2K1NS{
nEndPos[nEndPos.length-1] = nFileLength; cU[^[;4J<
} r2xXS&9!|
} H?a1XEY/
V9 J`LQ\0
W[R^5{k`
//启动子线程 !VzbNJ&'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !%lcn O
for(int i=0;i<nStartPos.length;i++) uexm|5|
{ Nj^:8]D)0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /E32^o|,>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c(j|xQ\pE
nStartPos,nEndPos,i); Bokpvd-c7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c2o.H!>
fileSplitterFetch.start(); F3Y/Miw
} 4[P]+Z5b+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |ler\"Eu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pqtk1=U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", er44s^$
nEndPos = " + nFileLength); MKPw;@-
// fileSplitterFetch[nPos.length-1].start(); Pf/_lBtL
]aDU*tk
`Jv~.EF%
//等待子线程结束 S5(VdMd"^
//int count = 0; }QzF.![~z
//是否结束while循环 <} BuU!
boolean breakWhile = false; *)|EWT?,
#<k L.e[
jY|fP!?[
while(!bStop) Ui43&B
{ W-8U~*/
write_nPos(); `m_('N
Utility.sleep(500); ^OZ*Le
breakWhile = true; =K:)%Qh
y~Ts9AE
m~;}8ObQE
for(int i=0;i<nStartPos.length;i++) 9[@K4&
{ )&F]j
if(!fileSplitterFetch.bDownOver) Q8GI;`Rb
{ XN Gw@$
breakWhile = false; O>tz;RU
break; /9o gg
} B(t`$mC
} 5BAGIO<w
if(breakWhile) ,CED%
break; ,3P@5Ef
6!T9VL\=H
q?0&&"T}
//count++; C>=[fAr mO
//if(count>4) SF.Is=b
// siteStop(); 98ot{+/LK
} AbA_s I<;
ah2L8jN"
`iZ){JfAH
System.err.println("文件下载结束！"); sogdM{tz\
} jV 982Y
catch(Exception e){e.printStackTrace ();} 'Z}3XVZEN
} 3[r9v!l
/t|Lu@&:Xo
w'Vm'zo
//获得文件长度 < pWk
public long getFileSize() Y=$PsDh!
{ KSgYf;
int nFileLength = -1; jxdX7aik
try{ ;^f ;<
URL url = new URL(siteInfoBean.getSSiteURL()); Usl963A#'F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EN-;@P9;C
httpConnection.setRequestProperty("User-Agent","NetFox"); oU)Hco"_k
yR$ld.[uf
X"EZpJ'W
int responseCode=httpConnection.getResponseCode(); X6-;vnlKN
if(responseCode>=400) iyJx~:
{ 66C_XT
processErrorCode(responseCode); !lxq,Whr{
return -2; //-2 represent access is error DcRvZH
} von<I
svRYdInBNu
>)*0lfxTZ
String sHeader; \<u
(b#4Z
EN/r{Cm$B
for(int i=1;;i++) SSn{,H8/j
{ PdqyNn=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t->I# t7
//Utility.log(in.readLine()); wB+X@AA
sHeader=httpConnection.getHeaderFieldKey(i); :um]a70
if(sHeader!=null) 1)t*l;.
{ b<27XZ@
if(sHeader.equals("Content-Length")) z2U^z*n{
{ ,!vI@>nhG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {v}BtZ
break; V: n\skM
} P^^WViVX
} ,lDOo+eE%:
else Ny5$IIFe
break; }!QVcu"+t/
} ksy]t|
} BFswqp:
catch(IOException e){e.printStackTrace ();} +lw8YH
catch(Exception e){e.printStackTrace ();} 9?tG?b0
srK9B0I
dZ|x `bIgs
Utility.log(nFileLength); Oh5aJ)"D
8k )i-&R
#<DS-^W!
return nFileLength; D9JHx+Xf>
} 0b}.!k9
9>r@wK'Pn
.&2~gA
//保存下载信息（文件指针位置） V`m9+<.1b
private void write_nPos() h9kwyhd"
{ gX]ewbPDQ
try{ o[%\W
output = new DataOutputStream(new FileOutputStream(tmpFile)); cRv#aV
output.writeInt(nStartPos.length); lf\x`3Vd
for(int i=0;i<nStartPos.length;i++) u;9a/RI
{ (*Z:ByA
// output.writeLong(nPos); p^)w$UL}}
output.writeLong(fileSplitterFetch.nStartPos); H,EGB8E2
output.writeLong(fileSplitterFetch.nEndPos); C#TP1~6
} Hm'aD2k
output.close(); ldt]=Sqy
} CU@}{}Yl
catch(IOException e){e.printStackTrace ();} |4rqj1*U
catch(Exception e){e.printStackTrace ();} \)i,`bz
} et=i@PB)
>%LY0(hY3
[ d`m)MW-
//读取保存的下载信息（文件指针位置） O!P7Wu
private void read_nPos() "V`5 $ur
{ ;KgDVq5
try{ $"ACg!=M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <"yL(s^u"
int nCount = input.readInt(); Nx"|10gC
nStartPos = new long[nCount]; n(W&GSj|u9
nEndPos = new long[nCount]; kS4YxtvB
for(int i=0;i<nStartPos.length;i++) sGx3O i
{ VIg6'
nStartPos = input.readLong(); U|Uc|6
nEndPos = input.readLong(); K[S)e!\.
} B.:1fT7lI
input.close(); \027>~u {
} j/;wxKW
catch(IOException e){e.printStackTrace ();} }#S1!TU
catch(Exception e){e.printStackTrace ();} fr`Q 5!0
} a n0n8l
xlH3t&i7
VfwH:
private void processErrorCode(int nErrorCode) K>TEt5
{ mpQu:i|W
System.err.println("Error Code : " + nErrorCode); e*Y<m\*
} t N4-<6
k*D8IB
FKUo^F?z
//停止文件下载 3taGb>15
public void siteStop() 2R W~jn"
{ frc9
bStop = true; \BX9Wn*)a
for(int i=0;i<nStartPos.length;i++) SgssNv
fileSplitterFetch.splitterStop(); gq@8Z AWn
}rUAYr~VZ
K0D|p$v
} N6`U)=2o>h
} tu(^D23
//负责部分文件的抓取 'bsHoO
**FileSplitterFetch.java O*.n;_&
*/ 7 IJn9b
package NetFox; d2TIG<6/
@v3)N[|d
efE=5%O
import java.io.*; -9;?k{{[T
import java.net.*; !2>@:CKX
I9m9`4BK
'Lw8l `7
public class FileSplitterFetch extends Thread { d]:G#<.
[!MS1vc;
KuW>^mF(I
String sURL; //File URL #c":y5:
long nStartPos; //File Snippet Start Position Xvoz4'Gme
long nEndPos; //File Snippet End Position 9Ofls9]U
int nThreadID; //Thread's ID ><S(n#EB
boolean bDownOver = false; //Downing is over v??$z#1F3
boolean bStop = false; //Stop identical 'sNiJ>
FileAccessI fileAccessI = null; //File Access interface &n#yxv4
{> 8?6m-
A\W)uwyN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W\j)Vg__e
{ 9|[uie
this.sURL = sURL; \Rb:t}
this.nStartPos = nStart; &W c$VDC
this.nEndPos = nEnd; UvM4-M%2JN
nThreadID = id; 3o0ZS^#eB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t\a|Gp W
} m OE!`fd
Pf<yLT]
W/b)OlG"2
public void run() !dU$1:7
{ <=D a
while(nStartPos < nEndPos && !bStop) 7S^G]g!x
{ ?L0k|7
H5&._
tK/.9qP
try{ VumM`SH
URL url = new URL(sURL); X/90S2=P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8UXRM :Z"
httpConnection.setRequestProperty("User-Agent","NetFox"); /nuz_y\J
String sProperty = "bytes="+nStartPos+"-"; rGXUV`5Na
httpConnection.setRequestProperty("RANGE",sProperty); (x?Tjyzw
Utility.log(sProperty); eG8l^[
:=TIq
erbk(
InputStream input = httpConnection.getInputStream(); Cl!(F6K*
//logResponseHead(httpConnection); h_+
H0sTL#/L\
Dg"szJ-
byte[] b = new byte[1024]; R dwt4A+
int nRead; y Vm>Pj6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RPte[tq
{ ?w'86^_z
nStartPos += fileAccessI.write(b,0,nRead); 5ya^k{`+ZO
//if(nThreadID == 1) P9f`<o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J|DZi2o
} *8m['$oyV
Ie(.T2K
&e;Qabwxva
Utility.log("Thread " + nThreadID + " is over!"); Ox&G [
bDownOver = true; a!-J=\>9
//nPos = fileAccessI.write (b,0,nRead); <F(2D<d{;)
} 3l41"5Fy&
catch(Exception e){e.printStackTrace ();} .RJMtmp
} v=0G&x=/
} m%apGp'=1
gGUKB2)
h9CTcWGt
//打印回应的头信息 :?BK A0E
public void logResponseHead(HttpURLConnection con) qy)~OBY
{ ~IjID
for(int i=1;;i++) h=:/9O{H
{ 7>BfHb
String header=con.getHeaderFieldKey(i); h]k$K
if(header!=null) ^bfZd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vr'cR2
Utility.log(header+" : "+con.getHeaderField(header)); L 1!V'Hm{
else 5TB6QLPEwY
break; \#t)B J2
} 0 }od Q#
} KNd<8{'.
]VLseF
?z&%VU"
public void splitterStop() v[^8_y}A`
{ kDWEgnXK,v
bStop = true; z|D*ymz*EY
} PC<_1!M]
;-kDJi
9g5h~Ma
} ?X6}+
)3:0TFS}}k
=!^ gQ0~4
/* bNVeL$'
**FileAccess.java 9yC22C:
*//文件访问(定位，写) 9tPRQM7
package NetFox; *Z_4bR4Q
import java.io.*; w"s@q$}]8M
s{yw1:
dM^Z,;u
public class FileAccessI implements Serializable{ -"dt3$ju
mQ"uG?NE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uoI7' :Nv
RandomAccessFile oSavedFile; U\tx{CsSz
long nPos; /z*Z+OT2
]>VG}e~b
wqF?o
public FileAccessI() throws IOException % (y{Sca
{ d9M[]{
this("",0); ()?83Xj[c
} K8_v5
! I0xq"
P$#:$U@
public FileAccessI(String sName,long nPos) throws IOException Z%qtAPd
{ \toU zTT
oSavedFile = new RandomAccessFile(sName,"rw"); QE\ [EI2
this.nPos = nPos; i9DD)Y<
oSavedFile.seek(nPos); QH9t |l
} nm,LKS7
Lr$Mk#'B
/D3{EjUE=
public synchronized int write(byte[] b,int nStart,int nLen) x1.S+:
{ r@{TN6U
int n = -1; 7PX`kI
try{ {}$7Bp
oSavedFile.write(b,nStart,nLen); Lz'VQO1U=
n = nLen; MVsFi]-
} Nhjq.&
catch(IOException e) ZP<<cyY
{ nTEN&8Y>R
e.printStackTrace (); TQF+aP8[L
} F^75y?
j )6
IT_I.5*A2
return n; KkA)p/
} k||t<&`Ze
W-=6:y#A
V*uE83x1
} E[]5Od5#
MYWkEv7
;=ddv@
/* "d_wu#fO)
**SiteInfoBean.java %L+q:naZe
*/ 5 8bW
package NetFox; J,2V&WuV0r
b|d-vnYE
[>O!~
public class SiteInfoBean { 50^ux:Uv+N
o8bdL<
"?I#!t%'
private String sSiteURL; //Site's URL ~|V^IJZ22
private String sFilePath; //Saved File's Path mLX/xM/T?/
private String sFileName; //Saved File's Name 0@ Y#P|QF
private int nSplitter; //Count of Splited Downloading File ]%' AZ`8
A9$x8x*Lt
Yq+1kA
public SiteInfoBean() Lnr9*dm6q
{//nSplitter的缺省值为5 NBYJ'nA%;f
//default value of nSplitter is 5 ]:|B).
this("","","",5); 6p9fq3~7Y
} )>iOj50n3
;o_F<68QP
cMw<3u\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k{}> *pCU
{ <+roY"
sSiteURL= sURL; r )F;8(
sFilePath = sPath; j[G`p^ul
sFileName = sName; 4b8G 1fm
this.nSplitter = nSpiltter; s,HbW%s
utlr|m Xc
u,sR2&Fe
} ~||0lj.D
_%w680b'
<^5!]8*O
public String getSSiteURL() z5E%*]
{ !+GYu;_
return sSiteURL; mci> MEb
} *]$B 9zVs!
7'G;ijx
M.W X&;>
public void setSSiteURL(String value) n|(lPbD
{ nf.Ox.kM)
sSiteURL = value; )4yP(6|lx
} H+v&4}f
k^J8 p#`6
^q:-ZgM>
public String getSFilePath() "4N&T#
{ I|Oco?Q"
return sFilePath; <LHhs<M'
} n5:uG'L\
Qs6<(zaqkt
c4Ebre-Oa
public void setSFilePath(String value) 380`>"D
{ po| Ux`u
sFilePath = value; F2"fOS
} E }L Hp
kpm;ohd
F-&tSU,
public String getSFileName() 66yw[,Y
{ J=g)rd[`
return sFileName; ,;k+n)
} 9/ <3mF@E
TZn 15-O
F.9}jd{
public void setSFileName(String value) .wfydu)3
{ u`pTFy
sFileName = value; g'"~'
} Qb536RpcTY
5ZCu6A
Q:}]-lJg
public int getNSplitter() w#A)B<Y/"
{ h4Crq Yxa_
return nSplitter; V6]6KP#D
} Jw)JV~/0
J'44j;5&
-ng1RA>
public void setNSplitter(int nCount) !/FRL<mp
{ R\j~X@vI
nSplitter = nCount; R9XU7_3B
} +VIA@`4
} @8d 3
XT7m3M
#<{v~sVp&
/* {6i|"5_j
**Utility.java ejN/U{)jK'
*/ zakhJ
package NetFox; ?qh-#,O9B
HsY5wC
9&+]YYCS-
public class Utility { 7;>|9k
t7=D$ua
a_?sJ
public Utility() /%@;t@BK4
{ /jv/qk3i
\"lz,bT
Lqgrt]L_"
} vDjH $ U
}b_Ob
//线程睡眠 3>O|i2U
public static void sleep(int nSecond) o[Iu9.zJpy
{ %>KbaM1b
try{ >0^<<=m
Thread.sleep(nSecond); !~#zd]0x;
} UU=]lWib
catch(Exception e) k^5Lv#Z
{ p9v:T1?
e.printStackTrace (); tv#oEM9esl
} =uP? ?E
} U1\7Hcs$
-Vn#Ab_C
//日志 b3A0o*
public static void log(String sMsg) 0|&@)`
{ Ho &Q}<(
System.err.println(sMsg); O8]e(i
} 80lei
R%UTYRLUn
-WC0W
public static void log(int sMsg) nFnM9 pdMK
{ +B*]RL[th
System.err.println(sMsg); 7l* &Fh9;
} 2`o @L
} ]$smFF
"U\RN
t2[/eM.G
/* qTJhYxm
**TestMethod.java jTa\I&s,A
*/ gN/<g8
package NetFox; F0$w9p
y4-kuMYR
g=Z52y`N<
public class TestMethod { ACRuDY
]az(w&vqg2
'=dQ$fs
public TestMethod() mnm ZO}
{ ///xx/weblogic60b2_win.exe Qs1p
try{ Oe5rRQ$O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wf8{v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4=Th<,<
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2Q6;SF"Z
fileFetch.start(); K(;qdIr
} f,G*e367:
catch(Exception e){e.printStackTrace ();} =gVMt
-1Q24jrO-
8iIp[9~=
} q`xc h[H
+ktv:d
:\^b6"}8
public static void main(String[] args) f@i#Znkf*?
{ <K CI@
new TestMethod(); N@d~gE&^
} 5,Fq:j)MxW
} yCQvo(V[F
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