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)); eMHBY6<~=
} $U*b;'o
for(int i=0;i<nEndPos.length-1;i++) Pp{Re|.
{ KE$I!$zO
nEndPos = nStartPos[i+1]; _bsAF^ ;
} ~<Eu @8+_
nEndPos[nEndPos.length-1] = nFileLength; t=(d, kf
} CdZS"I
} g \;,NW^
:{8,O-
8uh^%La8b.
//启动子线程 ,8Eg/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k-CW?=
for(int i=0;i<nStartPos.length;i++) lE=&hba
{ dbe\ YE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f;{K+\T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z;'5A2
nStartPos,nEndPos,i); {TOz}=R"3h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {JGXdp:SB
fileSplitterFetch.start(); DH9p1)L'
} _&SST)Y|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A>9IE(C_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >;s!X(6b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u{J\X$]
nEndPos = " + nFileLength); zg}#X6\G<_
// fileSplitterFetch[nPos.length-1].start(); v#^_|
S UBrFsA
I+GP`=\
//等待子线程结束 j|-{*t{/x
//int count = 0; s#BSZP
//是否结束while循环 As>-9p>v
boolean breakWhile = false; r"4&.&6
8"=E0(m
?B{,%2+
while(!bStop) P*!~Z*"
{ 9O4\DRe5c
write_nPos(); |s!<vvp]
Utility.sleep(500); -`cNRd0n
breakWhile = true; Z,_EhEm
Y 8Dn&W
nvInq2T1
for(int i=0;i<nStartPos.length;i++) ,R$U(,>_0
{ E51'TT9
if(!fileSplitterFetch.bDownOver) P[K42mm
{ y F;KyY{
breakWhile = false; "2_nN]%u-
break; %|(Cb!ySX
} UA3!28Y&E3
} W.sH
if(breakWhile) /Z1>3=G by
break; oAt{#v
{>h,@
],|;
//count++; f\u5=!kjN
//if(count>4) 9i`MUE1Sh
// siteStop(); !*!i&0QC~R
} fn3DoD+I
/P[@o
ALi3JU
System.err.println("文件下载结束！"); &BOG&ot
} yD yMI
catch(Exception e){e.printStackTrace ();} t~V?p'a0ys
} u`gY/]y!
LL%s$>c65A
uB;PaZG?{
//获得文件长度 lPA:ho/`:
public long getFileSize() 3J}/<&wv
{ 5?HoCz]l
int nFileLength = -1; z^Y4:^L~I
try{ }>yQ!3/i
URL url = new URL(siteInfoBean.getSSiteURL()); 92D :!C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W61nJ7@
httpConnection.setRequestProperty("User-Agent","NetFox"); zwgO|Qg;
;\54(x}|K
z)fg>?AGr
int responseCode=httpConnection.getResponseCode(); yP"D~u
if(responseCode>=400) ./_4D}
{ S]<%^W'
processErrorCode(responseCode); OV`#/QL
return -2; //-2 represent access is error `ZPV.u/
} a=r^?q'/
eMOnzW|h
}&Ul(HR
String sHeader; mNQ*YCq.
nV_[40KP_
^$;5ZkQy
for(int i=1;;i++) evE$$# 6R
{ umI6# Vd`=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Senb_?
//Utility.log(in.readLine()); U&OE*dq
sHeader=httpConnection.getHeaderFieldKey(i); Eemk2>iP?
if(sHeader!=null) >U62vX"
{ qlg?'l$03)
if(sHeader.equals("Content-Length")) I,7n-G_'
{ oLc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FQBAt0
break; ~+&Z4CYb
} 4*?JU v
} ^~DClZ
else 0#!Z1:Y
break; /9<62F@zJ"
} WV,j <x9w
} ]-8yZWal
catch(IOException e){e.printStackTrace ();} 7b hJt_`Q
catch(Exception e){e.printStackTrace ();} $@eFSA5k,7
^2eH0O!
G0Wv=tX|
Utility.log(nFileLength); %R-KkK<S
QvDD
B'-L-]\H
return nFileLength; b\^9::oY
} i3<ZFR
m:C|R-IL
^ jT1q_0
//保存下载信息（文件指针位置） GU]_Z!3
private void write_nPos() !A#(bC
{ ct@i]}"`
try{ ,_U3p ,
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ir$:e*E>
output.writeInt(nStartPos.length); o(3`-ucD`
for(int i=0;i<nStartPos.length;i++) y R_x:,|g
{ 95^-ptO{1`
// output.writeLong(nPos); >-4kO7.V
output.writeLong(fileSplitterFetch.nStartPos); F:cenIaBF
output.writeLong(fileSplitterFetch.nEndPos); q|xic>.
} )kt,E}609
output.close(); O;SD90
} iNEE2BPp
catch(IOException e){e.printStackTrace ();} *S\/l-D
catch(Exception e){e.printStackTrace ();} :'K%&e?7s
} t_{rKb,
B$&&'i%
#]e](j>]
//读取保存的下载信息（文件指针位置） ;`}b .S=n
private void read_nPos() $v~I n
{ #(o(p
try{ r|JZU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RtScv
int nCount = input.readInt(); BV512+M
nStartPos = new long[nCount]; -: 8[
nEndPos = new long[nCount]; gs9VCaIa
for(int i=0;i<nStartPos.length;i++) f}?q
{ A"no!AN
nStartPos = input.readLong(); '`/w%OEVC5
nEndPos = input.readLong(); U Y')|2y 5
} <"}WpT
input.close(); 3`>nQ4zC
} ZE"Z_E;r
catch(IOException e){e.printStackTrace ();} XE.Y?{,R$
catch(Exception e){e.printStackTrace ();} 6),VN>j
} "&N1$$
X.hVMX2B
YMIX|bj6Y
private void processErrorCode(int nErrorCode) mFeoeI,Jv
{ U(u$5
System.err.println("Error Code : " + nErrorCode); #hP&;HZ2>"
} _%6Vcy
&+-]!^2o
"M4gl
//停止文件下载 Ilv _.
public void siteStop() _5SA(0D#9
{ "%fvA;
bStop = true; =d`/BDD
for(int i=0;i<nStartPos.length;i++) ui4*vjd
fileSplitterFetch.splitterStop(); qFg"!w
YDdY'd`*
e=w.7DSE
} TP?HxO_C
} b8TwV_&|X
//负责部分文件的抓取 5$Aiez~tBq
**FileSplitterFetch.java mZb[Fi
*/ t*cVDA&K
package NetFox; i}}}x
HA::(cXL
HT6+OK(~dJ
import java.io.*; us3fBY'
import java.net.*; -3eHJccB
)kuw&SH,
^.; x
public class FileSplitterFetch extends Thread { XY1b_uY
8 !+eq5S3
oCR-KR>{Q
String sURL; //File URL n> O3p ~
long nStartPos; //File Snippet Start Position v#o<. Ig
long nEndPos; //File Snippet End Position $H2HVJ
int nThreadID; //Thread's ID (&ABfm/t
boolean bDownOver = false; //Downing is over 'k9dN \ev
boolean bStop = false; //Stop identical OX*5 yT{
FileAccessI fileAccessI = null; //File Access interface xXm:S{I
- |j4u#z
TWk1`1|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2$%E:J+2:$
{ @N,I}_9-
this.sURL = sURL; \`$RY')9|!
this.nStartPos = nStart; sCwX|
this.nEndPos = nEnd; R6/vhze4L2
nThreadID = id; 'q9='TOk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RmcQGQ
} K^fH:pV
-+w^"RBV
N>'|fNx]
public void run() T{Rhn V1
{ c DO<z
while(nStartPos < nEndPos && !bStop) dLIZ)16&
{ ]f~mR_E
_aLml9f W
=Zc Vywz;+
try{ QwL'5ws{q
URL url = new URL(sURL); )i{B:w\ ^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =(U&?1R4
httpConnection.setRequestProperty("User-Agent","NetFox"); >7^i>si
String sProperty = "bytes="+nStartPos+"-"; [r"`rBw
httpConnection.setRequestProperty("RANGE",sProperty); ~Q/G_^U:
Utility.log(sProperty); BO3%p
KW5u.phv
Q'n]+%YN
InputStream input = httpConnection.getInputStream(); !mtq?LV
//logResponseHead(httpConnection); XexslzI
PK7 kpC
A/+bwCDP
byte[] b = new byte[1024]; _]~= Kjp
int nRead; ;mYj`/Yj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c _faW
{ JSOgq/\
nStartPos += fileAccessI.write(b,0,nRead); />E:}1}{
//if(nThreadID == 1) ,@]rvI6x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E8QY6gKF
} Hjtn*^fo^
,F)9{ <r]
@3@oaa/v
Utility.log("Thread " + nThreadID + " is over!"); [J71aH
bDownOver = true; |rg4j
//nPos = fileAccessI.write (b,0,nRead); }3&~YBx;:
} #0wH.\79
catch(Exception e){e.printStackTrace ();} wqyrs|P
} Q+]9Glz9
} y@?t[A#v
fX[6 {
Z?}yPsOb
//打印回应的头信息 f.cQp&&]r
public void logResponseHead(HttpURLConnection con) RN"O/b}qQ
{ %W[#60
for(int i=1;;i++) K@UQ O
{ TUaW'
String header=con.getHeaderFieldKey(i); "X7;^yY
if(header!=null) O5?Gv??@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C0bOPn
Utility.log(header+" : "+con.getHeaderField(header)); nD8CP[bRo
else ca{u"n
break; 'eRJQ*0F
} %Qc5_of
} '3MCb
B}YpIb]d
ozr82
public void splitterStop() T.{sO`
{ u^!c:RfE?
bStop = true; 861!p%y5
} _:Jra
n6f
5sc`L
} S`qa_yI)Ed
Z[{k-_HgAm
uK5&HdoM
/* Q-:IE T
**FileAccess.java E3a^)S{
*//文件访问(定位，写) n)'5h &#
package NetFox; rL=_z^.P
import java.io.*; |d B`URP
N3`EJY_|V
=gjq@N]lAW
public class FileAccessI implements Serializable{ S)h0@;q
bim 82<F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jbU=D:|
RandomAccessFile oSavedFile; >P/Nb]C
long nPos; 1 ynjDin<
."#M X!
ief~*:5
public FileAccessI() throws IOException Fu%%:3_
{ j.FW*iX1C
this("",0); b+g(=z+
} a9=pZ1QAG
:{ }]$+|)\
}9qbF+b
public FileAccessI(String sName,long nPos) throws IOException ?pAO?5Z:}
{ Vif0z*\e{
oSavedFile = new RandomAccessFile(sName,"rw"); ]S=AO/'
this.nPos = nPos; 0Ek+ }`
oSavedFile.seek(nPos); /s\_"p
} +?!x;qS^
m<DiYxK
.-Xp]>f,
public synchronized int write(byte[] b,int nStart,int nLen) \ tK{!v+
{ y[W<vb+F
int n = -1; E_[)z%&n2
try{ *61+Fzr
oSavedFile.write(b,nStart,nLen); 4KkjBPV
n = nLen; H*Tc.Ie
} [9:'v@Ph
catch(IOException e) JFvVRGWB
{ RKY~[IQ,
e.printStackTrace (); 9EE},D
} hpqM fz1
Y}/e"mp
`a!:-.:v
return n; !p4y@U{
} p..O;_U
z DP
c)HHc0KD
} 9b/7~w.
)tRqt9Th*
sU/R$Nbr
/* |Mm9QF;iA
**SiteInfoBean.java H</Mh*Fl2G
*/ 99\;jz7
package NetFox; ?ep'R&NV
A@W/
/ox9m7Fz7
public class SiteInfoBean { U%7| iK
b~1]}9TJ
}nQni?
private String sSiteURL; //Site's URL (L{Kg U&{$
private String sFilePath; //Saved File's Path XM+o e0:[
private String sFileName; //Saved File's Name U8T"ABvFP
private int nSplitter; //Count of Splited Downloading File b* QRd
/%#LA
=`b/ip5
public SiteInfoBean() 4rmSo^vK
{//nSplitter的缺省值为5 {x+"Ru~7,
//default value of nSplitter is 5 ^+ hJ& 9W
this("","","",5); ]$StbBP
} cPemrNxydN
<HLe,
*6-fvqCv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Zewx*Y|
{ wQ7G_kVp
sSiteURL= sURL; lE8M.ho\
sFilePath = sPath; 0{8^)apII
sFileName = sName; AF=9KWqf
this.nSplitter = nSpiltter; Xy74D/ocui
P~>E
j &#A 9!
} hU}!:6G%[P
98%M`WY
<h$Nh0
public String getSSiteURL() 6(Qr!<
{ tj:Q]]\M
return sSiteURL; b)SU8z!NV&
} 8fn7!
PjH[8:,
PFqc_!Pm
public void setSSiteURL(String value) f1a >C
{ 3H_mR j9th
sSiteURL = value; y;!qE~!3
} `Jvy~T
bN,>,hj
aAlES< r
public String getSFilePath() LIo3a38n?y
{ C)7T'[
return sFilePath; +B 4&$z
} $#cZJ@;]
YpAJ7E|7
"k8Yc<`u
public void setSFilePath(String value) b.`<T"y
{ ;{n@hM*O
sFilePath = value; eb])=
} NV|[.g=lg
6z/ct|n
[3yzVcr~4
public String getSFileName() 4k HFfc
{ RGeM.
return sFileName; :QndeUw
} -:hiLZJ7-
<K~> :4c
9>t
public void setSFileName(String value) 9@Iz:!oqb
{ '`-W!g[ >
sFileName = value; NF}QQwG3
} $[L8UUHY<8
$`2rtF
fZ9EE3
public int getNSplitter() yqy5i{Y
{ )yV|vn
return nSplitter; ~*3obZ2>2
} }Htnhom0n
|Ef\B]Ns
pJ` M5pF
public void setNSplitter(int nCount) A9*( O)
{ [j6EzMN
nSplitter = nCount; Quc,,#u
} yGNZw7^(
} uCc.dluU
*wgHa6?+7
Q}KNtNCpx
/* 5E~?hWAv
**Utility.java iqzl(9o.D
*/ sr0.4VU1
package NetFox; F{#m~4O
*K9I+t"g
U4DQ+g(A
public class Utility { 0WasE1t|
[-Zp[
]Qo.X~]
public Utility() nkKiYr
{ bYuQ"K A$
0_}^IiG
wq[\Fb`
} [0_JS2KE
2Xu?/yd
//线程睡眠 &1O!guq%
public static void sleep(int nSecond) y$n7'W6
{ [m9Pt]j@
try{ ]L'FYOfrpx
Thread.sleep(nSecond); U({20
} hEO#uAR^Z
catch(Exception e) 4H7 3a5f
{ 9;Z2.P"w
e.printStackTrace (); dXkgWLI~
} "4VC:"$f
} | HkLl^
M*DFtp<
//日志 x=+R0ny
public static void log(String sMsg) a,o>E4#c
{ _xg4;W6M=
System.err.println(sMsg); }pE8G#O&
} \htL\m^$9
q|E0Y
R^%uEP
public static void log(int sMsg) *cjH]MQ0Ak
{ u/Os
System.err.println(sMsg); ~c e?xr|
} R&z)
} qz|`\^
)+^1QL
omxBd#;F$
/* T&?0hSYt
**TestMethod.java z|Z<S+=f
*/ #n=b*.
package NetFox; kzA%.bP|
U'pm5Mc\q
DzZ)aE
public class TestMethod { tEz6B}
P;&rh U^[
oDyrf"dl
public TestMethod() -Cb<T"7
{ ///xx/weblogic60b2_win.exe aR }|^ex
try{ *wNX<R.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ryz [A:^G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #z|\AmZ\
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~[@Gj{6p0
fileFetch.start(); bYr;~ ^
} ~<M/<%o2*
catch(Exception e){e.printStackTrace ();} sGNVZx
dg%Orvuz
us&!%`
} 6E9y[ %+
)P6n,\
NLe+
public static void main(String[] args) ]J^9iDTTA
{ .s4hFB^n
new TestMethod(); U] 2fV|Hn
} Jjb(lW
} 9aLS%-x!+
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