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)); GdeR#%z
} R 4QwWSBJ
for(int i=0;i<nEndPos.length-1;i++) e=)*O
{ ZX6=D>)u
nEndPos = nStartPos[i+1]; ;:\,x
} lEbR)B,
nEndPos[nEndPos.length-1] = nFileLength; k,iV$,[TF
} Ox*T:5
} -_*XhD
B m@oB2x)
?Wz(f{Hm
//启动子线程 k=~pA iRDN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >wk=`&+V@
for(int i=0;i<nStartPos.length;i++) RyQ\5^z
{ gc:p@<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h8= MVh(I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9 roth
nStartPos,nEndPos,i); YSz$` 7i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?CW^*So
fileSplitterFetch.start(); P}WhE
} _E<O+leWf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X1V}%@3:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MN M>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]#-/i2-K
nEndPos = " + nFileLength); i2}=/
// fileSplitterFetch[nPos.length-1].start(); 5A]LNA4i
f+aS2k(e>
Ta\8>\6
//等待子线程结束 9Glfi@.
//int count = 0; Ysc|kxLb
//是否结束while循环 '"fU2M<.
boolean breakWhile = false; nP{sCH 1
Z=Y_;dS9
0CVsDVA
while(!bStop) \%?8jQ'tX
{ 7- 3N
write_nPos(); ocA'goI-
Utility.sleep(500); z'}=A
breakWhile = true; c;8"vJ
a2=uM}Hsp
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for(int i=0;i<nStartPos.length;i++) Or#+E2%1E
{ # /,2MQ
if(!fileSplitterFetch.bDownOver) pT;-1c%:
{ c>WpOZ,
breakWhile = false; g*r{!:,t
break; VRQbf
} [cLU*:
} =.f +}y
if(breakWhile) :*&9TNUE@
break; 73s3-DS,
bR8 HGH28
z2nUul(2
//count++; PxVI{:Uz
//if(count>4) 6v2RS
// siteStop(); 3{I=#>;
} #9hXZr/8
x [{q&N!"`
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System.err.println("文件下载结束！"); mLk6!&zN
} e<O;pM:
catch(Exception e){e.printStackTrace ();} Fb{`a[&
} >upXt?
kSDa\l!W]
hKzBq*cV
//获得文件长度 *CPB5s
public long getFileSize() sg6w7fp>
{ oA3W {
int nFileLength = -1; E_![`9i
try{ %L\{kUam
URL url = new URL(siteInfoBean.getSSiteURL()); K,C$J I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M\?uDC9
httpConnection.setRequestProperty("User-Agent","NetFox"); pW3)Y5/D
@a.6?.<L
1l|A[G
int responseCode=httpConnection.getResponseCode(); ;LF)u2x=
if(responseCode>=400) F<ocY0=9p
{ C>`.J_N
processErrorCode(responseCode); 9*TS90>a
return -2; //-2 represent access is error ),y!<\oQ
} rm)SfT<
S `m-5
JX\T {\m#
String sHeader; ;*g*DIR
H6PXx
kO,VayjT
for(int i=1;;i++) wUIsi<Oj
{ /VmCN]2AZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9?l?G GmQ
//Utility.log(in.readLine()); (4{ C7
sHeader=httpConnection.getHeaderFieldKey(i); srChY&h?<
if(sHeader!=null) gSv[4,hXd
{ L%o65
if(sHeader.equals("Content-Length")) 8W1K3[Jj<
{ .y;\puNq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bDh:!M
break; ]lB3qEn<
} 8%2rgA
} WDoKbTv
else ><#2O
break; mS)|6=Y
} vzohq1r5
} &` 00/p
catch(IOException e){e.printStackTrace ();} &8X .!r`f
catch(Exception e){e.printStackTrace ();} n$OE~YwP{
hk5E=t~&
l#5~t|\
Utility.log(nFileLength); B::4Qme
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7$1fy0f[l
return nFileLength; S`W'G&bCj
} a$xeiy9
iKF$J3a\2f
dY4k9p8
//保存下载信息（文件指针位置） iBtjd`V*
private void write_nPos() +C'TW^
{ >TlW]st
try{ j2o1"
output = new DataOutputStream(new FileOutputStream(tmpFile)); !0!U01SWa
output.writeInt(nStartPos.length); /.|A
for(int i=0;i<nStartPos.length;i++) V&mH#k
{ cz7CrK~5
// output.writeLong(nPos); ySixYt
output.writeLong(fileSplitterFetch.nStartPos); y;{^Ln4{
output.writeLong(fileSplitterFetch.nEndPos); D8@nkSP
} x:A-p..e
output.close(); ?2?S[\@`0U
} T]Tdx.B
catch(IOException e){e.printStackTrace ();} fd5ZaE#f
catch(Exception e){e.printStackTrace ();} OD?y
} l}Q"Nb)
#90[PASx
jIx8k8
//读取保存的下载信息（文件指针位置） AK@`'$
private void read_nPos() m{bZRkt
{ n2xLgK=
try{ Ss#@=:"P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 68koQgI[^
int nCount = input.readInt(); ( K6~Tj
nStartPos = new long[nCount]; `x{.z=xC
nEndPos = new long[nCount]; wDT>">&d
for(int i=0;i<nStartPos.length;i++) N"Qg\PS_
{ 3wN?|N
nStartPos = input.readLong(); Yo~LckFF
nEndPos = input.readLong(); "wnpiB}
} ;t;Y.*&=S
input.close(); PJxak3
} VxkCK02k
catch(IOException e){e.printStackTrace ();} ZR;8rZ](
catch(Exception e){e.printStackTrace ();} z.2r@Psk
} (|0.m8D~D
E ;BPN
sJ))<,e5I
private void processErrorCode(int nErrorCode) _KB{J7bs<a
{ V>b2b5QAH,
System.err.println("Error Code : " + nErrorCode); }J ei$0x
} '%zN
W>5vRwx00
,hpH!J'5f/
//停止文件下载 ~ON1Zw[+
public void siteStop() *#&k+{a^2
{ ^CZCZ,v
bStop = true; d5@X#3Hd
for(int i=0;i<nStartPos.length;i++) ADv^eJJ|
fileSplitterFetch.splitterStop(); &a%WM
a|DsHZ^6^
Q^z=w![z
} prNhn:j
} IVI~1~
//负责部分文件的抓取 ./'~];&
**FileSplitterFetch.java FAQr~G}
*/ mu6039qy
package NetFox; s<[A0=LH
,O:EX0
h>}ax\h
import java.io.*; H~A"C'P3#
import java.net.*; _j:UGMTi(U
;{<aA 5
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public class FileSplitterFetch extends Thread { +h0PR?
$&cz$jyY
:J^qjAV
String sURL; //File URL :ozV3`%$(
long nStartPos; //File Snippet Start Position vU=9ydAj?
long nEndPos; //File Snippet End Position "$XYIuT
int nThreadID; //Thread's ID yXJ]U \ %
boolean bDownOver = false; //Downing is over J|VK P7
boolean bStop = false; //Stop identical 9T(L"9r-e
FileAccessI fileAccessI = null; //File Access interface ;B&^yj&;
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c_ La^HS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bGbqfO`
{ 2t+D8 d|c<
this.sURL = sURL; Fi mN?s
this.nStartPos = nStart; nz4<pvC,*
this.nEndPos = nEnd; *IC^IC:
nThreadID = id; >[ eW">:>K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ')B =|T)
} >T<6fpXuk2
>^a$
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public void run() yL0f1nS
{ 7ftR4
while(nStartPos < nEndPos && !bStop) ,4[dLWU
{ \gLxC
k`Nyi)AGe
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try{ w/ TKRCO3
URL url = new URL(sURL); l , ..5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {Fbg]'FQ
httpConnection.setRequestProperty("User-Agent","NetFox"); ]eE 1n2
String sProperty = "bytes="+nStartPos+"-"; .*BA 1sjE
httpConnection.setRequestProperty("RANGE",sProperty); #~L!pKM
Utility.log(sProperty); 5sCFzo<=vh
sf(iE(o
o]Gguw5W{
InputStream input = httpConnection.getInputStream(); z~,mRgc$B
//logResponseHead(httpConnection); |6aJwe+*
3UdU"d[75
v:E;^$6Vn
byte[] b = new byte[1024]; iOXZ]Xj5
int nRead; i[\w%(83Fi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) / s,tY74'5
{ e@E17l-
nStartPos += fileAccessI.write(b,0,nRead); dL-i)F
//if(nThreadID == 1) Vtr3G.P^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ly;I,)w
} tJNIr5o
zh\$t]d<I
4o<*PPA1
Utility.log("Thread " + nThreadID + " is over!"); w5`#q&?
bDownOver = true; CEuWw:)
//nPos = fileAccessI.write (b,0,nRead); (89Ji'dc
} C5|db{=\.*
catch(Exception e){e.printStackTrace ();} <47k@Ym
} 7h%4]
} *m9{V8Yi2
LN4qYp6)G
4S|=/f
//打印回应的头信息 k;k}qq`d
public void logResponseHead(HttpURLConnection con) iK#/w1`
{ l4rMk^>>
for(int i=1;;i++) ldGojnS
{ W^es;5
String header=con.getHeaderFieldKey(i); VPt9QL(
if(header!=null) `5q ;ssu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yEq#Dr
Utility.log(header+" : "+con.getHeaderField(header)); *^]~RhjB
else Tzzq#z&F
break; {CtR+4KD
} d|XmasGN
} "xe=N
=7%oE[
V|'1tB=;*1
public void splitterStop() !nd*W"_gQ/
{ @Y}uZ'jt'
bStop = true; 7{e=="#*
} @5.e@]>ZM
MPIlSMe
X8i(~ B
} ySe$4deJ
]N^*tO
YuQ~AE'i
/* lwT9~Hyp
**FileAccess.java D'b#,a;V
*//文件访问(定位，写) %T!J$a)qf
package NetFox; ?P/AC$:|I
import java.io.*; 6BocGo({
tu0aD%C
bUZ_UW
public class FileAccessI implements Serializable{ `pL^}_>|GM
Zp&@h-%YoD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !lTda<;]
RandomAccessFile oSavedFile; /*$hx@ih
long nPos; fuUm}N7
@*>Sw>oet
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public FileAccessI() throws IOException t{dSX?<nt
{ AQss4[\Dx
this("",0); }fZ`IOf
} h5"Ov,K3[
\,&9
@?kM'*mrZM
public FileAccessI(String sName,long nPos) throws IOException $g10vF3
{ D\1k.tI
oSavedFile = new RandomAccessFile(sName,"rw"); >\2:\wI
this.nPos = nPos; kL>d"w
oSavedFile.seek(nPos); @F~LW6K
} ^e Gue
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En6H%^d2
public synchronized int write(byte[] b,int nStart,int nLen) p`F9Amb
{ *|% ^0#$c
int n = -1; B=Ym x2A9]
try{ . ]@=es
oSavedFile.write(b,nStart,nLen); 2HD]?:Fk7
n = nLen; k|YWOy@D~
} yClx` S(
catch(IOException e) +Qxu$#
{ 71fk.16
e.printStackTrace (); mee$"Y
} l|/LQ/
-nbMTY}
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return n; )IL #>2n?
} .8WXC
({^9<Us
e>}}:Ud
} \HZ9S=
"TcW4U9
g(C|!}ex/
/* 4|?{VQ
**SiteInfoBean.java Oakb'
*/ 7.Kc:7
package NetFox; #A7jyg":
C?4JXW
d[D&J
public class SiteInfoBean { S6d`ioi-
kc `V4b%
uC3:7
private String sSiteURL; //Site's URL SOZPZUUEJ
private String sFilePath; //Saved File's Path %dST6$Z
private String sFileName; //Saved File's Name &fC!(Oy
private int nSplitter; //Count of Splited Downloading File ao" %WX
Sh6JF574T
+pm[f["C.
public SiteInfoBean() :}:3i9e*2
{//nSplitter的缺省值为5 mmXm\]r>4
//default value of nSplitter is 5 V/d/L3p
this("","","",5); }x0- V8
} ^Xb7[+I6
;Q;[*B=kE
l_tw<`Ep
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %V`F!D<D
{ #H?t!DU
sSiteURL= sURL; !$;a[Te
sFilePath = sPath; YgUH'P-
sFileName = sName; WE6a'
this.nSplitter = nSpiltter; B/JO~;{
-t2T(ha
7dG79H
} *OJ/V O
-|k)tvAm
LQ11ba
public String getSSiteURL() J5p"7bc
{ [#Lc]$
return sSiteURL; #11NPo9
} Uxfl_@lJ
57a2^
D4Al3fe
public void setSSiteURL(String value) `;|5
{ ^9OUzTF
sSiteURL = value; [D-Q'"'A
} 9^"b*&>P
g"s$}5{8:
,#FLM`
public String getSFilePath() 1"7Sy3
{ xkNyvqcw
return sFilePath; Rlnbdb;!k
} 1OLqL
5!YA o\S
%J:SO_6
public void setSFilePath(String value) bzDIhnw
{ 8P7"&VYc8
sFilePath = value; 2kAx>R
} S{4z?Ri, '
?\KM5^eX
Hs?e0Z=N
public String getSFileName() E!BPE>
{ 7]xm2CHx5
return sFileName; ]M/9#mD9~
} t^]$!H
fkSO( C)
7cAXd#sI
public void setSFileName(String value) E:zF/$tG
{ -K,-h[o
sFileName = value; ]<(]u#g_d
} Y2B&go
_lzyMEdr
\^(0B8|w
public int getNSplitter() Uoya3#4 G
{ [ EFMu;q
return nSplitter; Djk C
} Uz cx6sw
2%*MW"Q
] Z8Vj7~
public void setNSplitter(int nCount) b2 _Yu^
{ t?o,RN:
nSplitter = nCount; b|Q)[y]
} QB.J,o*XD4
} CQel3Jtt.
du$|lxC
W$U0[^1
/* O#wpbrJ
**Utility.java ,B4VT 96*
*/ 6sIL.S~c)
package NetFox; PB%-9C0
L %ip>
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public class Utility { +^*iZ6{+7
PJxH7|GSi
'(? uPr
public Utility() }:0uo5B7
{ D7Y)?Z5A;
?USQlnr:R/
G} eUL|S
} 8WE{5#oi
0 a]/%y3V
//线程睡眠 ~~/xRs
public static void sleep(int nSecond) ^c~)/F/cF
{ LjL[V'JL
try{ f.24:Dw,
Thread.sleep(nSecond); ~GE$myUT\p
} =@TQ>Qw%b
catch(Exception e) o=FE5"t
{ eC5$#,HiC
e.printStackTrace (); ^pM+A6 XY
} +<,gB $j
} NmMIQ@K
;8!Z5H
//日志 dU\%Cq-G)
public static void log(String sMsg) *[=bR>
{ "V{yi!D{<
System.err.println(sMsg); G:x*BH+
} yj4+5`|f
#:T-hRu
pJN${
public static void log(int sMsg) 0$7.g!h?
{ cA6lge<{~
System.err.println(sMsg); XeBP`\>Ve
} .>z][2oz
} eIl]oC7*
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R/"x}B1d
/* qfcYE=
**TestMethod.java P0`Mdk371
*/ Y(.OF Q
package NetFox; 6<K6Y5<6
4v[~r1!V
g$. \
public class TestMethod { @( n^T
Ltjbxw"Qd
=]3tUD
public TestMethod() bc , p}
{ ///xx/weblogic60b2_win.exe D&HV6#
try{ i#%aTRKHd6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G,;,D9jO7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EyY.KxCB
SiteFileFetch fileFetch = new SiteFileFetch(bean); wP,JjPUt
fileFetch.start(); fDx9iHGv
} Mi~(aah
catch(Exception e){e.printStackTrace ();} eT2*W$
t>8XTqqi
Scv#zuv_
} iAa;6mH
"`6n6r42
(H+'X}1
public static void main(String[] args) Zo>]rKeV
{ A.UUW
new TestMethod(); {BHI1Uw
} pRSOYTebP
} Gycm,Cy
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