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)); o2!wz8
} 6o4Y]C2W{1
for(int i=0;i<nEndPos.length-1;i++) JJy.)-R
{ `\J,%J
nEndPos = nStartPos[i+1]; U<<XeSp
} 8&3KVd`
nEndPos[nEndPos.length-1] = nFileLength; {%c&T S@s
} WaSZw0U}y
} 06]"{2
U'@ ![Fp
z! :0%qu
//启动子线程 o+Fm+5t;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ako]34Rl,
for(int i=0;i<nStartPos.length;i++) KkCsQ~po
{ wlgR =l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D!&]jkUN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F ESl#.}
nStartPos,nEndPos,i); /h8100
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r+;k(HMY}[
fileSplitterFetch.start(); iP6?[pl8
} NuW6~PV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N9 h|_ax
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]A%~bQ7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \}W !
nEndPos = " + nFileLength); /}9)ZYMx
// fileSplitterFetch[nPos.length-1].start(); )YW"Zo8~!1
G|u)eW
wsB
//等待子线程结束 "RgP!
//int count = 0; AkCy C1
//是否结束while循环 !,]2.:{0z
boolean breakWhile = false; c#TV2@
oX7_v_:J\R
oRZe?h^r#
while(!bStop) 6j95>}@
{ #4<=Ira5
write_nPos(); !*S,S{T8
Utility.sleep(500); aW9\h_$
breakWhile = true; xjD."q
X8):R- J
kPoz&e_@
for(int i=0;i<nStartPos.length;i++) 9sI&d
{ *7b?.{
if(!fileSplitterFetch.bDownOver) Vh>|F}%E
{ uU%Z%O
breakWhile = false; LW k/h1
break; W8F@nY
} r+k&W
} E1SWZ&';
if(breakWhile) bo1J'pU
break; Swh\^/B8
E\TWPV'/
m^ Epw4eg
//count++; %7QSBL
//if(count>4) 31UxYBY
// siteStop(); S|af?IW
} ;hF}"shJN
+s^nT{B@\
a~?B/ g&_
System.err.println("文件下载结束！"); AN3oh1xe:
} suE8"v!sk
catch(Exception e){e.printStackTrace ();} [5ncBY*A7
} uQ|LkL%<^
4ETHaIiWp
m#[9F']Z`
//获得文件长度 #+i:s92],
public long getFileSize() B):ZX#
{ LcB+L](
int nFileLength = -1; ^+~5\c*
try{ cQ'x]u_
URL url = new URL(siteInfoBean.getSSiteURL()); 3iUJ!gK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h=\1ZQKC)
httpConnection.setRequestProperty("User-Agent","NetFox"); I L,lXB<
v|KIVBkbT
+r7hc;+G
int responseCode=httpConnection.getResponseCode(); ]=9 d'WL
if(responseCode>=400) %a|Qw(4\
{ oUO3,2bn
processErrorCode(responseCode); &nwS7n1eb
return -2; //-2 represent access is error pU'${Z~b
} ]#W7-Q;]
/q}(KJX
m(o`;
String sHeader; { ^^5FE)%
#!E`%' s]
nCQ".G
for(int i=1;;i++) E0/>E
{ RN|Bk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u})*6l.
//Utility.log(in.readLine()); 7r^Cs#b+I
sHeader=httpConnection.getHeaderFieldKey(i); (>E/C^Tc%
if(sHeader!=null) #d*0 )w
{ ({@"{
if(sHeader.equals("Content-Length")) 5D2mZ/
{ 5gV,^[E-z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DBG0)=SHy
break; v9FR
} ,]nRnI^
} :y`LF<
else \F-n}Z
break; ,|A6l?iV
} ?@Q0;LG
} }EYmz/nN
catch(IOException e){e.printStackTrace ();} :5$ErI
catch(Exception e){e.printStackTrace ();} ITg:OOQ
,A $IFE
~(-1mB,
Utility.log(nFileLength); v#d(Kj
~@*q8lC
otfmM]f
return nFileLength; ](v,2(}=
} cMF)2^w}
|d-x2M[
jSM`bE+"
//保存下载信息（文件指针位置） OI*ltba?
private void write_nPos() *aC[Tv[-P
{ [s`B0V`04
try{ [[]yQ "
output = new DataOutputStream(new FileOutputStream(tmpFile)); -G@uB_Cs
output.writeInt(nStartPos.length); he/rt#
for(int i=0;i<nStartPos.length;i++) G[]%1 _QCO
{ #d3_7rI0V
// output.writeLong(nPos); V=p"1!(
output.writeLong(fileSplitterFetch.nStartPos); e$P^},0/
output.writeLong(fileSplitterFetch.nEndPos); TB?'<hD:
} 0Ze&GK'Hf
output.close(); &WLN
} R9^vAS4t[O
catch(IOException e){e.printStackTrace ();} maHz3:
catch(Exception e){e.printStackTrace ();} wr:W}Z@pL
} FyWf`XTO
("ix!\1K@
38m9t'
//读取保存的下载信息（文件指针位置） qoH:_o8ClO
private void read_nPos() {5D%<Te
{ X@}7 #Vt
try{ .a :7|L#a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1Az&BZU[
int nCount = input.readInt(); 5+!yXkE^e
nStartPos = new long[nCount]; Pv,PS.,-
nEndPos = new long[nCount]; V6](_w!
for(int i=0;i<nStartPos.length;i++) :RukW.MR
{ $xdo=4;|
nStartPos = input.readLong(); pfIK9>i
nEndPos = input.readLong(); xzOvc<u
} EtPB_! +
input.close(); EPLHw
} {fDRVnI?
catch(IOException e){e.printStackTrace ();} 37:tu7e~c
catch(Exception e){e.printStackTrace ();} QxaMe8(
} Og1\6Q
?Fa$lE4
Rf8ZH
private void processErrorCode(int nErrorCode) IKnf
{ X_nbNql
System.err.println("Error Code : " + nErrorCode); Oi& 9FS
} )quQI)Ym
HJJ)DE7;
:UH*Wft1
//停止文件下载 m<z?6VC
public void siteStop() U&:-Vf~&
{ c(vi,U-hC
bStop = true; ;`c:Law4
for(int i=0;i<nStartPos.length;i++) qi7*Jjk>90
fileSplitterFetch.splitterStop(); E$4H;SN \
B8T5?bl
w5s&Ws
} w5)KWeGa
} "N_@q2zF
//负责部分文件的抓取 /O$~)2^h
**FileSplitterFetch.java EZ/_uj2&SN
*/ ) ?kbHm
package NetFox; )'g4Ty
B*3_m _a
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import java.io.*; ".Q]FE@>
import java.net.*; RrrlfFms
0Bp0ScE|FA
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public class FileSplitterFetch extends Thread { }id)~h_@
.Jg<H %%f
<_pLmYI
String sURL; //File URL {wt9/IlG1
long nStartPos; //File Snippet Start Position Gdx%#@/
long nEndPos; //File Snippet End Position *L>usLh
int nThreadID; //Thread's ID |B$JX'_
boolean bDownOver = false; //Downing is over *gGw/jA/
boolean bStop = false; //Stop identical ^/Yk*Ny
FileAccessI fileAccessI = null; //File Access interface ^t<L
-{JReplc
K iXD1Zpz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s nxwe
{ ]Hi1^Y<
this.sURL = sURL; Q2]7|C
this.nStartPos = nStart; #')]~Xa
this.nEndPos = nEnd; U v>^ Z2
nThreadID = id; !@Vj&>mH$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J32{#\By
} `WC4:8
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S\sy^Kt~4:
public void run() xDekC~Zq
{ Bqa_l|
while(nStartPos < nEndPos && !bStop) oz:J.<j24Z
{ d3?gh[$
iH]0 YT.E
1 rbc}e
try{ j+/EG^*/
URL url = new URL(sURL); -~\7ZRP8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tVX|e2Y
httpConnection.setRequestProperty("User-Agent","NetFox"); n31nORx50
String sProperty = "bytes="+nStartPos+"-"; _uJ6Vy
httpConnection.setRequestProperty("RANGE",sProperty); R*LPwJuv
Utility.log(sProperty); a04S&ezj
jamai8
rc%*g3ryLG
InputStream input = httpConnection.getInputStream(); CnY dj~
//logResponseHead(httpConnection); 4U)%JK.ta
n Zx^ej\
lu.xv6+
byte[] b = new byte[1024]; F3Vvqt*2
int nRead; U;.cXU{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DX3jE p2
{ l<sWM$ez
nStartPos += fileAccessI.write(b,0,nRead); \B/( H)Cd*
//if(nThreadID == 1) HQ4WunH2Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AC fhy[,
} B1i'Mzm-4
\[+':o`LH
436SIh
Utility.log("Thread " + nThreadID + " is over!"); )F'hn+(B|G
bDownOver = true; 7A<}JaE!,
//nPos = fileAccessI.write (b,0,nRead); c-@EHv
} pAN$c"
catch(Exception e){e.printStackTrace ();} T%}x%9VO7
} +{)V%"{u:
} ,(c'h:@M
l~kxK.Ru
u6\W"LW
//打印回应的头信息 \vj xCkg{
public void logResponseHead(HttpURLConnection con) s\3ZE11L
{ P8CIKoKCV
for(int i=1;;i++) <_bGV
{ =*y{y)B^g
String header=con.getHeaderFieldKey(i); b%X}{/n
if(header!=null) }_Sgor83n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i~HS"n
Utility.log(header+" : "+con.getHeaderField(header)); 4HXNu,T'
else W"xRf0\V
break; 2V+[:>F
} 2@ZuH^qhk
} CFY4PuI"!
W$" >\A0%
!$o9:[B
public void splitterStop() @ eP[*Q
{ AucX4J<
bStop = true; e=u}J%|
} yaX%<KBa\
N *n?hN
><6g-+*k
} bV@5B#] 2R
2fUz}w (
3URrK[%x`
/* 6XeqK*r*
**FileAccess.java }T=\hM
*//文件访问(定位，写) ,}Ic($To
package NetFox; (jE[W:
import java.io.*; \ $9n `
hJ V*
h&{>4{
public class FileAccessI implements Serializable{ u/?;J1z:
P(zquKm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3e^'mT
RandomAccessFile oSavedFile; rf&nTDaWI
long nPos; 90$`AMR
YH!` uU(Lh
zhwajc
public FileAccessI() throws IOException j7Lw(AJ
{ lGX_5R
this("",0); `qbsDfq@
} <QE/p0.
\hZ9in`YlR
~48mCD
public FileAccessI(String sName,long nPos) throws IOException TqMy">>
{ 4dvuw{NZ
oSavedFile = new RandomAccessFile(sName,"rw"); 8,(5Q
this.nPos = nPos; !O8vr4=
oSavedFile.seek(nPos); L_7-y92<W
} iW<B1'dp
YPav5<{a
P}Ule|&LK
public synchronized int write(byte[] b,int nStart,int nLen) 5 %aT
{ R:DW>LB
int n = -1; j6)@kW9x
try{ V0 OT_F
oSavedFile.write(b,nStart,nLen); jvos)$;L-
n = nLen; C0Ti9
} ldm=uW
catch(IOException e) l.i&.;f
{ C{):jH,Rf
e.printStackTrace (); y3C$%yv0
} [mk!]r
0IjQqI
"Mmvf'N
return n; Ndx ]5
} 4;d9bd)A
.W%{j()op
|"a%S,I'
} )<jT;cT!&
$PNIuC?=
kQm\;[R
/* enJE#4Z5&s
**SiteInfoBean.java qu/59D
*/ 47XQZ-}4
package NetFox; #r)c@?T@j
"ealYveu
u_U51C\rb
public class SiteInfoBean { j^Z3
$ p{Q]|ww
/CN^">|_
private String sSiteURL; //Site's URL nZM|8
private String sFilePath; //Saved File's Path yf7p0;$?
private String sFileName; //Saved File's Name N8l(m5Kk,k
private int nSplitter; //Count of Splited Downloading File ';!02=-@
5lC"10
/z+}xRS
public SiteInfoBean() t=ry\h{Pc
{//nSplitter的缺省值为5 Hv1d4U"qM
//default value of nSplitter is 5 Mzxy'UV
this("","","",5); X/nb7_M
} m:~s6c6H
iwfv t^
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `+QrgtcEy4
{ Ip4SdbU
sSiteURL= sURL; hQgi--Msw'
sFilePath = sPath; ,*V{gpC7
sFileName = sName; !g~xn2m$R
this.nSplitter = nSpiltter; PTvP;
|nj%G<
<H~ (iQ
} ZUMzWK5Th
>g6:{-b^a
@4b"0ne}h
public String getSSiteURL() #sEbu^
{ #.%;U' #O
return sSiteURL; i5*sG^<$H
} @hWt.qO3s
7Q.?]k&
Y0U<l1(|
public void setSSiteURL(String value) ^YKEc0"w(
{ Rj%q)aw'
sSiteURL = value; }o?@
} DP*[t8
8\t~*@"
7@rrAs-"Z
public String getSFilePath() fN>o465I6
{ j4Cad
return sFilePath; H6*d#!
} $3%EKi
I/MYS5}
Zl.}J,0F
public void setSFilePath(String value) /'}O-h
{ A=|&N%lP'
sFilePath = value; O&irgc!
} %Ow,.+m
aC$hg+U$G
,?7URx*
public String getSFileName() W04-D
{ bY;ah;<
return sFileName; oO>mGl36H
} <D pi M`
j#0@%d
&B7X LO[
public void setSFileName(String value) q?{wRBVVB
{ 0\Qqv7>
sFileName = value; hn-9l1~!h
} TgVvp0F;
pl V]hu27K
+dk}$w[g
public int getNSplitter() QVI4<Rxg
{ QkwBw^'_5
return nSplitter; 7\K=8G
} Dw?nf
=ex71qj)
NS;,(v{*N
public void setNSplitter(int nCount) 4lE j/#}
{ /e6\F7
nSplitter = nCount; X61]N^y
} S=ebht=
} q3e%L
Sim\+SL{#
}^^X-_XT
/* sC48o'8(
**Utility.java AY{caM
*/ SI)u@3hl&w
package NetFox; J O`S
Lt.a@\J'_
">*PH}b
public class Utility { vz*QzVk1
kc\^xq~
iu2{%S)w
public Utility() [GX5jD#
{ JVFn=Mw
_1f!9ghT\
V,fSn:8%M
} egxh
$3|++?
//线程睡眠 A$Mmnu%
public static void sleep(int nSecond) 2}[)y\`t3
{ vZmM=hW~
try{ U|={LU
Thread.sleep(nSecond); *f=H#
} 1j "/}0fx
catch(Exception e) @S yGj#
{ mTT1,|
e.printStackTrace (); L\XnTL{
} /Zap'S/
} 9H$#c_zrq
X<m#:0iD
//日志 [*Nuw_l
public static void log(String sMsg) VChNDHiH
{ +;tXk
System.err.println(sMsg); U@!e&QPn
} +LCpE$H
nc!P !M
o nt8q8
public static void log(int sMsg) D$+9`
{ T$)&8"Xya
System.err.println(sMsg); +6-c<m|
} nxkbI:+t
} H[UV]qO,
+*]"Yo~]}
D.9qxM"Z>
/* W~z 2Q so
**TestMethod.java +hI:5(_
*/ @r^a/]5D
package NetFox; 9aFu51
+] >o@
8e:J{EG~
public class TestMethod { 3,=97Si=
F~2bCy[Z
*JDQaWzBd
public TestMethod() z^j7wMQ
{ ///xx/weblogic60b2_win.exe _8Cw_
try{ GuPxN}n 5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c!vtQ<h-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tAO,s ZW
SiteFileFetch fileFetch = new SiteFileFetch(bean); sygxV
fileFetch.start(); SKt&]H
} a,i k=g
catch(Exception e){e.printStackTrace ();} %wWJVq}jx
:sAb'6u1EU
GX?R# cf
} 7ESSx"^B
~(OG3`W!
{Z0(V"Q
public static void main(String[] args) Yl4XgjG
{ Is1P,`*!
new TestMethod(); ^)oBa=jL4
} Cp4 U`]
} ix2V?\
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