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)); 0\QYf0o
} IZ|c<#r6
for(int i=0;i<nEndPos.length-1;i++) kaV%0Of]
{ 57'q;I
nEndPos = nStartPos[i+1]; V5cb}xx
} IOn`cbV:
nEndPos[nEndPos.length-1] = nFileLength; %~ ;nlDw
} 'wegipK~R
} [p2g_bI8yK
rK*hTjVn
9F/|`
//启动子线程 J: L-15
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R A*(|n>
for(int i=0;i<nStartPos.length;i++) #^"hqNwA
{ d5N)^\z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1 VPg`+o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tbL1g{Dz,
nStartPos,nEndPos,i); R %Rv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K lPm=
fileSplitterFetch.start(); ;D6x=v=2
} Vj#%B.#Zbf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *G8'Fjin'T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hQ\#Fhu7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s$IcDuBu
nEndPos = " + nFileLength); k*A4;Bm
// fileSplitterFetch[nPos.length-1].start(); 1x^W'n,HtK
,^UcRZ8.H
+#&el//
//等待子线程结束 2l]C55p)s
//int count = 0; qb#V)
//是否结束while循环 [N'r3
boolean breakWhile = false; @G^j8Nl+J}
OJh+[bf"
j 8~Gv=(h
while(!bStop) \"<GL;
{ 11nO<WH
write_nPos(); +H5 jRw
Utility.sleep(500); tyBg7dP
breakWhile = true; Lh8#I&x
Yj|c+&Ng
iPRJA{$b_
for(int i=0;i<nStartPos.length;i++) LR 8e|H0
{ WV9[DFU
if(!fileSplitterFetch.bDownOver) gDUoc*+h
{ BV_a-\Sa=
breakWhile = false; 0TuNA\Ug+
break; 8' WLm
} mP`,I"u
} T%z!+/=&^
if(breakWhile) {|t?
break; X.r!q1_c
dja9XWOg
J:M<9W
//count++; z.Ve#~\
//if(count>4) h0ZW,2?l
// siteStop(); -NI@xJO4(;
} E!O(:/*
tPMgZ
DVeF(Y3&
System.err.println("文件下载结束！"); g/J^K*3]
} @i1.5z
catch(Exception e){e.printStackTrace ();} t's5~
} <#J<QYF&2
b W`)CWd
0Zp<=\!;
//获得文件长度 +eH=;8
public long getFileSize() >ZOZv
{ ;9- 4J
int nFileLength = -1; 's%ct}y\J
try{ ir1RAmt%
URL url = new URL(siteInfoBean.getSSiteURL()); Jq=>H@il
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1dXO3hot
httpConnection.setRequestProperty("User-Agent","NetFox"); T!O3(
cmC&s'/8`D
TO;]9`~;Mu
int responseCode=httpConnection.getResponseCode(); 3mnLV*aRt
if(responseCode>=400) J>&dWKM3
{ d&3I>E$UP
processErrorCode(responseCode); hKH Q!`&v
return -2; //-2 represent access is error A`mf 8'nTG
} L2Qp6A6S
b~N|DKj
)l/C_WEK
String sHeader; p-ii($~}
v6, o/3Ex
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for(int i=1;;i++) :EmMia-)J
{ Ky{I&}+R|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :O_<K&
//Utility.log(in.readLine()); yO69p
sHeader=httpConnection.getHeaderFieldKey(i); Zzzi\5&gU
if(sHeader!=null) iJ~iJ'vf
{ |cBF-KNZ
if(sHeader.equals("Content-Length")) w{UKoU
{ _{@}Fd?o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1OJD\wc
break; okW)s*7
} 6CzvRvA*P
} ,J4a~fPf
else -a#AE|`
break; +[go7A$5
} j^R~ Lt4
} W(3~F2
catch(IOException e){e.printStackTrace ();} e?'k[ES^
catch(Exception e){e.printStackTrace ();} .LVOaxT
-2mOgv
F$pd]F!#
Utility.log(nFileLength); " kJWWR
`5aypJf1
eWt>^]H~
return nFileLength; E*#60z7F
} OEqe^``!
T;vPR,]rz
MjeI?k}LJ
//保存下载信息（文件指针位置） B7^n30+L
private void write_nPos() h4xf%vA(;
{ %EhU!K#[
try{ )#TJw@dNf^
output = new DataOutputStream(new FileOutputStream(tmpFile)); _TeRsA
output.writeInt(nStartPos.length); iPi'5g(a
for(int i=0;i<nStartPos.length;i++) "r(pK@h
{ Vste$V
// output.writeLong(nPos); D +%k1
output.writeLong(fileSplitterFetch.nStartPos); /o3FK
output.writeLong(fileSplitterFetch.nEndPos); y8 u)Q
} qSs^}eN
output.close(); rcb/X`l=
} rG'k<X~7
catch(IOException e){e.printStackTrace ();} 6xQe!d3>s3
catch(Exception e){e.printStackTrace ();} fP4IOlHkE
} a5g{.:NfO
RwLdV+2\R`
dg@/HLZ
//读取保存的下载信息（文件指针位置） rsj}hS$
private void read_nPos() 0BZOr-i
{ #~qp8 w
try{ U@ QU8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4BL,/(W] x
int nCount = input.readInt(); wOl-iN=
nStartPos = new long[nCount]; SYhspB
nEndPos = new long[nCount]; %3B>1h9N
for(int i=0;i<nStartPos.length;i++) .0/Z'.c8
{ E;e2{@SX2K
nStartPos = input.readLong(); iPL'JVPZ
nEndPos = input.readLong(); K%#C+`Ij
} bI0+J)
input.close(); ~Am %%$
} 17i@GnbNb
catch(IOException e){e.printStackTrace ();} .j@n6RyN
catch(Exception e){e.printStackTrace ();} @ dU3d\!}
} 4'e8VI0
'F<e)D?
@g5]w&o_
private void processErrorCode(int nErrorCode) vX)Y%I
{ Sgk{NM7|k
System.err.println("Error Code : " + nErrorCode); /9^0YC;Y*
} x \{jWR%
aWK7 -n
QU;C*}0Zl
//停止文件下载 ~Q\uP(!D
public void siteStop() { J%$.D(/
{ DcM+K@1E4^
bStop = true; `SbX`a0p2
for(int i=0;i<nStartPos.length;i++) T$B4DQ
fileSplitterFetch.splitterStop(); ~x\Q\Cxp
@WE$%dr
mM%BO(X{=
} mT$tAwzTC{
} "N"k8,LH
//负责部分文件的抓取 nUu|}11(
**FileSplitterFetch.java , |B\[0p
*/ N8Q{4c
package NetFox; =!Cvu.~},
]8z6gDp
'vClZGQ1
import java.io.*; mTbPzZ4
import java.net.*; ?5M2DLh~
YZJP7nN
RH0a\RC!G
public class FileSplitterFetch extends Thread { N%i<DsK.u6
9~af\G
{u][q &n
String sURL; //File URL PQay sdb
long nStartPos; //File Snippet Start Position Q)dns)_x
long nEndPos; //File Snippet End Position 'hWRwP|
int nThreadID; //Thread's ID D1/$pA+B
boolean bDownOver = false; //Downing is over =jHy6)6w
boolean bStop = false; //Stop identical NP/2gjp
FileAccessI fileAccessI = null; //File Access interface 51usiOq
:S2MS{>Mo
L zy|<:K+$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MM7gMAA.mz
{ o8"xoXK5xf
this.sURL = sURL; 4x>e7Kf
this.nStartPos = nStart; t)+dW~g
this.nEndPos = nEnd; F`3As 9b:
nThreadID = id; pr?(5{BL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9(]j e4Cn
} |e(x< [s5
L0~O6*bk
s2kynQ#a
public void run() MeS$+9jV(
{ zvg&o)/[
while(nStartPos < nEndPos && !bStop) {S~$\4vC!
{ 2J <Z4Ap
14zzWzKx
l"#,O$x"#@
try{ +r"$?bw'
URL url = new URL(sURL); lvffQ_t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =Q/i<u
httpConnection.setRequestProperty("User-Agent","NetFox"); exvsf|
String sProperty = "bytes="+nStartPos+"-"; upKrr
httpConnection.setRequestProperty("RANGE",sProperty); #nz$RJsX
Utility.log(sProperty); $Q4b~
RT9@&5>il
^)I:82"|?
InputStream input = httpConnection.getInputStream(); d_hcv|%
//logResponseHead(httpConnection); Aed"J5[a
{F[Xe_=#"
%m`QnRX?D
byte[] b = new byte[1024]; ij^!TY[0
int nRead; -OxHQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a#=-Aj-
{ =7>~u
nStartPos += fileAccessI.write(b,0,nRead); l{g(z!
//if(nThreadID == 1) rY.:}D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,j<"~"] =
} ,)G,[ih
b*i+uV?
&kBs'P8>
Utility.log("Thread " + nThreadID + " is over!"); !8].Z"5J
bDownOver = true; =%`"
//nPos = fileAccessI.write (b,0,nRead); zKr(Gt8
} [x,&Gwa
catch(Exception e){e.printStackTrace ();} K<(RVh
} }vIm C [
} .}wir,
!NtY4O/
m~A/.t%=
//打印回应的头信息 t=#)3C`Q}
public void logResponseHead(HttpURLConnection con) I 3PnyNZ
{ c#Bde-dh
for(int i=1;;i++) m`cG&Ar5
{ 1<UQJw45
String header=con.getHeaderFieldKey(i); WDq3K/7\
if(header!=null) -M}iDBJx>#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AH+J:8k
Utility.log(header+" : "+con.getHeaderField(header)); 511q\w M
else Heu@{t.[!D
break; xh$[E&2u
} 3IIlAzne;
} z7o59&
o-_a0j
-u{:39y{n
public void splitterStop() eNX-2S
{ hv6>3gbr
bStop = true; =v-D}eJQ=
} 5o*x?P!$
%qMk&1
iuEdm:pW
} \kx9V|A'
=v8q
t!tBN
/* ;uy/Vc5,Y
**FileAccess.java \=JKeL|6[S
*//文件访问(定位，写) ' BpRiN
package NetFox; R0WJdW#
import java.io.*; "d'@IN
vjb{h'v
;_!;D#:
public class FileAccessI implements Serializable{ JT+P>\\];'
{<lV=0]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qa=;Elp:[
RandomAccessFile oSavedFile; })Jp5vv
long nPos; _]g6 3q
n"JrjvS
WW.=>]7;
public FileAccessI() throws IOException 2rk_ ssvs
{ 51A>eU|
this("",0); H:`r!5&Qb5
} R!O'DM+
$d'Gh2IGA
_<8n]0lX3
public FileAccessI(String sName,long nPos) throws IOException @S{,g;8
{ .._wTOSq
oSavedFile = new RandomAccessFile(sName,"rw"); <H.Ml>q:r
this.nPos = nPos; s<myZ T$
oSavedFile.seek(nPos); 2IGAZ%%
} 4H'9y3dk
MxYCMe4S[
)vw3Y88
public synchronized int write(byte[] b,int nStart,int nLen) iVD9MHT4
{ qVf~\H@
int n = -1; G2mv6xK'
try{ -C\m'T,1
oSavedFile.write(b,nStart,nLen); tw;`H( UZ^
n = nLen; >o@WT kF]
} ,E_hG3}}
catch(IOException e) 9s}--_k?F2
{ W>Zce="_gN
e.printStackTrace (); {pVD`#Tl[
} E|No$QO)
]LD@I;(_
"UE'dWz
return n; Ji=E 1R
} [Ga9^e$Zv
3]wV`mD
IuPwFf)
} K]RkKMT,
C; ! )<(Vw
u+hzCCwtR
/* 7[Y<5T]
**SiteInfoBean.java x;ujR<
*/ AE@*#47
package NetFox; \i{=%[c
Nj?,'?'O}
<#:"vnm$j
public class SiteInfoBean { Y1+f(Q
pCv=rK@
2+0'vIw}
private String sSiteURL; //Site's URL Hf#/o{=~}
private String sFilePath; //Saved File's Path 4rv3D@E
private String sFileName; //Saved File's Name FX\ -Y$K
private int nSplitter; //Count of Splited Downloading File m@OgT<E]_
++xEMP)
KVJiCdg-
public SiteInfoBean() DI+kO(S
{//nSplitter的缺省值为5 [~ fJ/
//default value of nSplitter is 5 vQztD_bX%
this("","","",5); `6UW?1_Z5
} \ ddbqg?`
_uL m!ku
! XA07O[@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e%"L79Of6)
{ Krz[ f
sSiteURL= sURL; NFsMc0{
sFilePath = sPath; %A?Ym33
sFileName = sName; Si!W@Jm
this.nSplitter = nSpiltter; w+ bMDp
]kR 93
`XQM)A
} 74QWGw`,
n ,`!yw
<vOljo
public String getSSiteURL() wOINcEdx
{ EY':m_7W
return sSiteURL; 6MF%$K3
} tFXG4+$D
X#IVjc:&L
+\SbrB P
public void setSSiteURL(String value) "h\{PoG
{ ^KmyB6Yg
sSiteURL = value; BT>8
} Z3=t"
qd"*Td
P5kkaLzG
public String getSFilePath() db4Ol=
{ LKtr>u
return sFilePath; (V}DPA
} s+9q:
$}N'm
HX?5O$<<N
public void setSFilePath(String value) EPW Iu)A
{ :43K)O"
sFilePath = value; jO3Z2/#
} Q lql(*
'3aDvV0
vV,H@WK
public String getSFileName() sLPFeibof5
{ t: r
return sFileName; <5G*#0gw
} d'J))-*#UO
qVx0VR1:
8g^OXZ
public void setSFileName(String value) ="z\
{ f?[IwA`
sFileName = value; b2duC
} eLM_?9AZ!R
r)q6^|~47
j'I$F1>Te
public int getNSplitter() D\bW' k]!
{ .^fq$7Y}7
return nSplitter; esWgYAc3{
} W_ngB[
^;!A`t
A{Jv`K
public void setNSplitter(int nCount) qJKD|=_
{ hT#[[md"
nSplitter = nCount; Rq<T2}K
} eZk [6H
} X2/`EN\
IX,/ZOZ|
<$K%u?
/* zH.DyD5T;
**Utility.java `b+f^6SJn
*/ Q9]7.^l
package NetFox; J#!:Z8b
eOE7A'X
P BpjE}[Q
public class Utility { `[2nxP>w`
0,{Dw9W:
j"7 z
public Utility() L Lm{:T7
{ Nj@k|_1
(G*--+Gn
gQCkoQi:j
} n'U*8ID
>| rID
//线程睡眠 EL;IrtU
public static void sleep(int nSecond) nxA Y]Q
{ mTwz&N\
try{ *}$T:kTH
Thread.sleep(nSecond); b`usRoD{+
} -:h5Ky"
catch(Exception e) LsS/Sk
{ '(7]jug
e.printStackTrace (); @{:E&K1f
} EgFV
} ;@Alr?y
MMN2XxS
//日志 bW7tJ
public static void log(String sMsg) v[q2OWcL
{ ;oH17
System.err.println(sMsg); qH: ` O%,
} \f}S Hh
&HNJ'
dP=1*
public static void log(int sMsg) _>9|"seR
{ DGz'Dn
System.err.println(sMsg); ,2qJXMg"=$
} MS)#S&
} J}Bg<[n
ka0T|$ u(s
Xw(e@:
/* Z2_eTC u
**TestMethod.java vRpMZ)e
*/ vQ#$.*Cvn
package NetFox; ; =ai]AYW
nU-.a5
H[wJ; l
public class TestMethod { Qx1ZxJz #
Oz#$x
KwndY,QD
public TestMethod() -v'7;L0K
{ ///xx/weblogic60b2_win.exe B;r U
try{ 3k`"%R.H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7hZCh,O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R] tHd=kf
SiteFileFetch fileFetch = new SiteFileFetch(bean); EDcR:Dw3
fileFetch.start(); `Rub"zM
} )mz [2Sfg
catch(Exception e){e.printStackTrace ();} 2 :u4~E3
22"M#:r$
f ?_YdVZ
} LYhgBG,
W$O^IC
%*wJODtB|
public static void main(String[] args) H$>D_WeJ
{ : ~"^st_[!
new TestMethod(); =QHW>v
} }QU9+<Z[r
} }L^Yoq]
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