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)); ][mc^eI0s|
} lyPXlt
for(int i=0;i<nEndPos.length-1;i++) W7 E-j+2
{ }:irjeI,
nEndPos = nStartPos[i+1]; pWp2{G^XB
} M}<=~/k`j
nEndPos[nEndPos.length-1] = nFileLength; +u2Co_FJ&
} D^~gq`/)
} {MtB!x
^`7t@G$ D
t<7WM'2<y
//启动子线程 7AiCQWf9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V Y3{1Dlf
for(int i=0;i<nStartPos.length;i++) Yp)U'8{h c
{ 00p 7sZU^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ed-gYL^<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w;(gi
nStartPos,nEndPos,i); {|%O)fr,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dfo9jYPf
fileSplitterFetch.start(); C"{on%
} (D{}1sZBQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l_%~X9"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $^!w`>0C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cn0Fz"d
nEndPos = " + nFileLength); ?X1#b2s
// fileSplitterFetch[nPos.length-1].start(); iQF}x&a<
e2fct|'
B@=<'/S\7
//等待子线程结束 AIyv;}5
//int count = 0; &^H "T6
//是否结束while循环 h~@+M5r,
boolean breakWhile = false; d/&|%Z r
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w-$w
while(!bStop) *PEuaRDN
{ o0L#39`'g
write_nPos(); A]9JbNV
Utility.sleep(500); :ct+.#
breakWhile = true; j1<1D@UO
dWy1=UQfP
Z]f2&
for(int i=0;i<nStartPos.length;i++) L'Zud,JKg
{ bEKLameKv
if(!fileSplitterFetch.bDownOver) ^j %UZ
{ Oy&'zigJ
breakWhile = false; q#`^EqtUF
break; Wwha?W>
} I={{VQ
} F21[r!3
if(breakWhile) ZL</
break; r<v%Zp
O:)IRB3
gpWS_Dw9
//count++; [R>
//if(count>4) ^mpB\D)q
// siteStop(); .}N^AO=
} =fG8YZ(
PNgMLQI6
ai4^NJn
System.err.println("文件下载结束！"); l`&6W?C
} c5e\ckqm^
catch(Exception e){e.printStackTrace ();} [r8 d+
} MF}Lv1/[-J
>EtP^Lu~f_
lg>AWTW[
//获得文件长度 lM*O+k
public long getFileSize() `uA&w}(G
{ Nh9!lBm*]
int nFileLength = -1; =bWq 3aP)P
try{ }!V<"d,!
URL url = new URL(siteInfoBean.getSSiteURL()); )c/y07er
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )`mF.87b&h
httpConnection.setRequestProperty("User-Agent","NetFox"); o$VH,2 QF
>;v0zE
zI!R-Nb
int responseCode=httpConnection.getResponseCode(); (H+[^(3d2
if(responseCode>=400) +c`C9RXk
{ ~4MjJKzA
processErrorCode(responseCode); m1i+{((
return -2; //-2 represent access is error yQ{_\t1Wd
} R"gm]SQ/
P&0cF{
X-#mv|3
String sHeader; lO> 7`2x=F
/kU@S
gsWlTI
for(int i=1;;i++) -_DiD^UcXn
{ ;}~Bv<#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z4ov
//Utility.log(in.readLine()); So%1RY{)
sHeader=httpConnection.getHeaderFieldKey(i); ',`4 U F
if(sHeader!=null) &W+G{W{3
{ G!Oq>7
if(sHeader.equals("Content-Length")) :TYzzl43
{ h_G|.7!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9~'Ip7X,!
break; 8/?uU]#Q
} }|"*"kxi!
} )^S^s>3
else b[o"Uq@8?
break; :YXQ9/iRr
} Qfu*F}
} ioa_AG6B
catch(IOException e){e.printStackTrace ();} <VR&=YJ
catch(Exception e){e.printStackTrace ();} '3UIriY6
dzNaow*0&V
,tF" 4|#
Utility.log(nFileLength); ^%$W S,
u|>U`[Zpj
nQ!#G(_nO
return nFileLength; MQH8Q$5D
} O\F^@;]F6
*Gh8nQbh
1qKxg
//保存下载信息（文件指针位置） k>;r9^D
private void write_nPos() i-s?"Fk
{ Doc'7P
try{ f9XO9N,hE:
output = new DataOutputStream(new FileOutputStream(tmpFile)); :G=1$gb
output.writeInt(nStartPos.length); b;`#Sea
for(int i=0;i<nStartPos.length;i++) VE"0VB.
{ Y1_6\zpA
// output.writeLong(nPos); lPQ Ut!xI
output.writeLong(fileSplitterFetch.nStartPos); VfC[U)w*vm
output.writeLong(fileSplitterFetch.nEndPos); .y_bV=
} $CwTNm?
output.close(); `{Di*
} p9}c6{Wp
catch(IOException e){e.printStackTrace ();} $17 v,
catch(Exception e){e.printStackTrace ();} 4U a~*58
} ="w8U'
}V#9tWW
h:Mn$VR,
//读取保存的下载信息（文件指针位置） p C2c(4
private void read_nPos() ^@LhUs>3
{ \ NSw<.
try{ ~v(M6dz~vk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RQ)!KlY
int nCount = input.readInt(); IfmIX+t?
nStartPos = new long[nCount]; M3;v3 }z<-
nEndPos = new long[nCount]; ?]:EmP
for(int i=0;i<nStartPos.length;i++) I;.! hV>E
{ ;/^]|
nStartPos = input.readLong(); ?)o4 Kt'h
nEndPos = input.readLong(); t k/K0u
} ny_ kr`$42
input.close(); {p*hNi)0
} nK%/tdq
catch(IOException e){e.printStackTrace ();} GE8D3V;*V
catch(Exception e){e.printStackTrace ();} {L-aXe{
} b}?@syy8
Gp3nR<+
0m YZ7S5g
private void processErrorCode(int nErrorCode) o`T<}z26
{ +yP[(b/
System.err.println("Error Code : " + nErrorCode); 8&A|)ur4
} 3|'#n[3
07LL)v~
W/ZahPPq
//停止文件下载 >?{iv1
public void siteStop() N7HbOLpM
{ Vh.;p.!e
bStop = true; OxHw1k
for(int i=0;i<nStartPos.length;i++) ;GgQ@s@
fileSplitterFetch.splitterStop(); 2*FWIHyf
u388Wj
gQpD]p%k
} Dss/>! mN
} zEPx
//负责部分文件的抓取 HHIUl,P
**FileSplitterFetch.java <j1d~XU}
*/ l;{N/cS
package NetFox; NtA|#"^
$6&GAJe
z Jo#3
import java.io.*; <E7Vbb9*
import java.net.*; j zmSFKg*
C`th^dqBV
B:A1W{l
public class FileSplitterFetch extends Thread { k.=S+#"}
(|a$N.e&K
x+*L5$;h
String sURL; //File URL Xv7U<q
long nStartPos; //File Snippet Start Position Puth8$
long nEndPos; //File Snippet End Position gcW{]0%L^
int nThreadID; //Thread's ID .t^UK#@#4
boolean bDownOver = false; //Downing is over c]aK N
boolean bStop = false; //Stop identical ;/)Mcx]n
FileAccessI fileAccessI = null; //File Access interface IB.'4B7
[;IDTo!<>
T?]kF-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #-gGsj;F
{ QC\g%MVG
this.sURL = sURL; rPo\Dz
this.nStartPos = nStart; TA@tRGP>
this.nEndPos = nEnd; )(?UA$"
nThreadID = id; H?=pWB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '[=yfh
} srChY&h?<
ll<9f)
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public void run() Lr24bv\
{ .y;\puNq
while(nStartPos < nEndPos && !bStop) 9OQ0Yc!3
{ ]lB3qEn<
.XLV:6
WDoKbTv
try{ -M>K4*%K
URL url = new URL(sURL); mS)|6=Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J^g,jBk
httpConnection.setRequestProperty("User-Agent","NetFox"); &` 00/p
String sProperty = "bytes="+nStartPos+"-"; =_?pOq
httpConnection.setRequestProperty("RANGE",sProperty); ,2 g M-
Utility.log(sProperty); ]4 K1%ZV
.n)!ZN
az\<sWb#
InputStream input = httpConnection.getInputStream(); h[-d1bKwS
//logResponseHead(httpConnection); =mi:<q
b5n]Gp
].k+Nzf_
byte[] b = new byte[1024]; z3vsz
int nRead; MKVfy:g%So
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x#:BE
{ ni"$[8U
nStartPos += fileAccessI.write(b,0,nRead); tkdBlG]!
//if(nThreadID == 1) e$ XY\{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 22al
} B \_d5WJ<
Hn#GS9d_?
'Ffy8z{&3
Utility.log("Thread " + nThreadID + " is over!"); OZ>)sL
bDownOver = true; j5,^9'
//nPos = fileAccessI.write (b,0,nRead); dK J@{d
} t> x-1vf%
catch(Exception e){e.printStackTrace ();} l?o-!M{
} !Ig|m+
} ##EB; Y
v ]/OAH6D
)y%jLiQv
//打印回应的头信息 ]< s\V-y
public void logResponseHead(HttpURLConnection con) R%Ui6dCLo
{ `FzYvd"N
for(int i=1;;i++) d4y9AE@k
{ FUyB"-<
String header=con.getHeaderFieldKey(i); s.R-<Y3
if(header!=null) 68koQgI[^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |b$>68:
Utility.log(header+" : "+con.getHeaderField(header)); F}6DB*
else wDT>">&d
break; Z{,GZT
} 3wN?|N
} Yo~LckFF
n) _dH/"
;t;Y.*&=S
public void splitterStop() PJxak3
{ VxkCK02k
bStop = true; Z>(r9R3{
} z.2r@Psk
(|0.m8D~D
E ;BPN
} sJ))<,e5I
[K cki+
V>b2b5QAH,
/* }J ei$0x
**FileAccess.java '%zN
*//文件访问(定位，写) W>5vRwx00
package NetFox; ,hpH!J'5f/
import java.io.*; e2]4a3
8)^B32
F_A%8)N
public class FileAccessI implements Serializable{ h4hN1<ky\
gk!E$NyE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Jv_.itc
RandomAccessFile oSavedFile; C5O5S:|'
long nPos; w5F4"nl#O}
./'~];&
FAQr~G}
public FileAccessI() throws IOException .]W;2G
{ {]wIM^$6+
this("",0); ~L-0~
} A}t%;V2
NFk}3w:
[##`Um
public FileAccessI(String sName,long nPos) throws IOException 403[oOj
{ YBb)/ZghY
oSavedFile = new RandomAccessFile(sName,"rw"); #O2wyG)oU
this.nPos = nPos; [8>z#*B
oSavedFile.seek(nPos); BdN8 ^W
} ?e F@Q!h
)v[XmJ>H~o
8F#osN
public synchronized int write(byte[] b,int nStart,int nLen) 63W{U/*aao
{ bGbqfO`
int n = -1; _fcS>/<a
try{ "j{i,&Y$_
oSavedFile.write(b,nStart,nLen); nz4<pvC,*
n = nLen; *IC^IC:
} >[ eW">:>K
catch(IOException e) ')B =|T)
{ >T<6fpXuk2
e.printStackTrace (); \|CPR6I
} YEzU{J
6cJ<9i &
` ^DjEdUN
return n; rwiw Rh
} %BUEX
_ Yfmxn8V
QE|`&~sme
} S_J,[#&
|xn#\epy@
G6ayMw]OF
/* m#tpbFAsc
**SiteInfoBean.java >lrhHU
*/ GL1'Zo
package NetFox; JPEIT
R{HV]o|qk
}91*4@B7
public class SiteInfoBean { AXs=1 e
5iVQc-m&
$9K(F~/
private String sSiteURL; //Site's URL pz{'1\_+9
private String sFilePath; //Saved File's Path )zU:
private String sFileName; //Saved File's Name ]*qU+&
private int nSplitter; //Count of Splited Downloading File axmsrjW#
7paUpQit
`ncNEHh7K
public SiteInfoBean() OTj,O77k
{//nSplitter的缺省值为5 ._?V%/
//default value of nSplitter is 5 %SAw;ZtQ:
this("","","",5); `OqM8U @
} ;j{7!GeKa
YTK^ijmU6x
MaO"#{i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gH[,Xx?BN!
{ Ojq]HM6f
sSiteURL= sURL; zJ+3g!
sFilePath = sPath; mzWP8Hlw
sFileName = sName; \<~}o I
this.nSplitter = nSpiltter; N2BI_,hI1
Z|G/^DK!
Us,)]W.S
} t2- ^-g6
FZF @
[#Y' dFQ
public String getSSiteURL() ciudRK63M
{ `5q ;ssu
return sSiteURL; yEq#Dr
} *^]~RhjB
8TE>IPjm
{CtR+4KD
public void setSSiteURL(String value) d|XmasGN
{ "xe=N
sSiteURL = value; MoD?2J
} V|'1tB=;*1
!nd*W"_gQ/
>O#grDXb
public String getSFilePath() 24ux
{ iXFP5a>|
return sFilePath; c pk^!@c
} 9'nH2,_
)0k']g5
n2{SV
public void setSFilePath(String value) Pao%pA.<
{ 2C$R4:Ssw)
sFilePath = value; ?P/AC$:|I
} 6BocGo({
o%`Xa#*Ly
im]g(#GnKh
public String getSFileName() +pf5\#l?
{ 6?qDdVR~]
return sFileName; #DFV=:|~
} <@G8ni
rv>^TR*,!
BQ/PGY>
public void setSFileName(String value) \L # INP4~
{ S{#cD1>.
sFileName = value; }^-<k0A4?
} 8 TiG3
P:C2G(V1AR
w8Vw1wW
public int getNSplitter() bc I']WgB-
{ HpVjee
return nSplitter; $g10vF3
} D\1k.tI
+*}{`L- :
5GQLd
public void setNSplitter(int nCount) e5?PkFV^a1
{ a.@qGsIH
nSplitter = nCount; :7g=b%;
} T6#CK
} WC,+Cn e
?wb+L
X^@I].
/* rJJ[X4$
**Utility.java vUA0FoOp
*/ Sv'y e
package NetFox; 5D Y\:AF
W_`A"WdT.
l@JSK;
public class Utility { lFSe?X^
h3* x[W
\4d.sy0&>-
public Utility() 0d^Z uTN
{ ({^9<Us
e>}}:Ud
!#2=\LUC
} ?GA&f2]a
ORN6vX(1
//线程睡眠 +7V{ABfGl
public static void sleep(int nSecond) zYY$D.
{ *sw7niw
try{ L';MP^
Thread.sleep(nSecond); CZ<~3bEF
} &HW1mNF9
catch(Exception e) X2|Y
{ 3+Qxg+<
e.printStackTrace (); en F:>H4
} (1R?s>3o
} qZv =
laKuOx}
//日志 Pmg)v!"
public static void log(String sMsg) .@q-B+Eg
{ iRV~Il#~!
System.err.println(sMsg); FR[ B v
} uX/$CM
;%C'FV e]
e({9]
public static void log(int sMsg) @f+8%I3D
{ oR1^/e
System.err.println(sMsg); N2'qpxOLI
} Z?P~z07
} }[+!$#
lv&mp0V+
!$;a[Te
/* YgUH'P-
**TestMethod.java *l+OlQI0+
*/ B/JO~;{
package NetFox; -t2T(ha
"9EE1];NT
*OJ/V O
public class TestMethod { -|k)tvAm
LQ11ba
WtulTAfN
public TestMethod() [#Lc]$
{ ///xx/weblogic60b2_win.exe #11NPo9
try{ Uxfl_@lJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 57a2^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'ly?P8h
SiteFileFetch fileFetch = new SiteFileFetch(bean); :<Y}l-x
fileFetch.start(); >_dx_<75&
} DZ7 gcC
catch(Exception e){e.printStackTrace ();} $ ,SF@BhO
{GDmVWG0q
mR\`DltoV
} :F,O
FWue;pw3
).` S/F
public static void main(String[] args) W7"{r)7
{ *[ #;j$m
new TestMethod(); A1)wo^,
} -oeL{9;
} uwf 5!Z:>
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