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)); X}GX6qAdt
} rw)!>j+&A
for(int i=0;i<nEndPos.length-1;i++) Eq_@xT0>
{ 24od74\
nEndPos = nStartPos[i+1]; Af\@J6viF7
} EuHQp7
nEndPos[nEndPos.length-1] = nFileLength; $bhI2%_`M
} z^wod
} p4uzw
U>n[R/~]
V'b4wO1RV
//启动子线程 ^4IJL",
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I!!cA?W
for(int i=0;i<nStartPos.length;i++) WReHep
{ %Ja0:e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &tUX(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2?qT,pN
nStartPos,nEndPos,i); 2a-]TVL3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jct=Nee|
fileSplitterFetch.start(); odL*_<Z
} E|-oUzt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =Fe4-B?I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U^}7DJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?* +>T@MH
nEndPos = " + nFileLength); I`+,I`~u
// fileSplitterFetch[nPos.length-1].start(); "uplk8iCJ
#y&5pP:@
y /vc\e
//等待子线程结束 xsU%?"r
//int count = 0; (e;/Smol
//是否结束while循环 Swf%WuDj
boolean breakWhile = false; J<0sT=/2$
QUkP&sz
r7R39#
while(!bStop) }x|q*E\
{ 9y[U\[H
write_nPos(); iYiTkq
Utility.sleep(500); &CQ28WG X
breakWhile = true; :/gHqEC24
#HP-ne; #
Jr'a_(~
for(int i=0;i<nStartPos.length;i++) +b_[JP2
{ X6}W]
if(!fileSplitterFetch.bDownOver) sMLXn]m
{ jc3Q3Th/zn
breakWhile = false; k"=*'
break; 2asRJ97qES
} tW!*W?
} $J<WFDn9
if(breakWhile) %$Fe[#1
break; \>9^(N
l_;6xkv4
%INkuNa8\
//count++; hKg +A
//if(count>4) IPn!iv)
// siteStop(); W2%@}IDm
} +mft
q`8 5-
x44V 9-o
System.err.println("文件下载结束！"); 7z{N}
} 0i5S=L`j
catch(Exception e){e.printStackTrace ();} $U/lm;{%
} *"OlO}o
*N: $,xf
:^paI
//获得文件长度 qHheF%[\5
public long getFileSize() 'cu14m_
{ oP T)vN?
int nFileLength = -1; ?x 0gI
try{ : &nF>
URL url = new URL(siteInfoBean.getSSiteURL()); 48S NI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yIr0D6L
httpConnection.setRequestProperty("User-Agent","NetFox"); /]0SF_dZ
2&pE
M*cF'go
int responseCode=httpConnection.getResponseCode(); FbMtor
if(responseCode>=400) y5KeUMcu
{ UlNiH
processErrorCode(responseCode); : Wtpg
return -2; //-2 represent access is error MGK?FJn_?
} 7}MnvWP
;xUo(^t7>
`<P:ly.
String sHeader; FjizPg/|!
>S0kiGDV{
/oJ &\pI
for(int i=1;;i++) 86cnEj=
{ m8 _yorz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M/lC&F(
//Utility.log(in.readLine()); @+~>utr
sHeader=httpConnection.getHeaderFieldKey(i); y$di_)&g
if(sHeader!=null) eB_r.R{
{ +*`kJ)uP
if(sHeader.equals("Content-Length")) K;Hgq4
{ 1R yE8DdP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gH,Pz
break; h 2JmRO
} =z"8#_3A
} t_16icF9U
else PJ&L7
break; $0OOH4
} &PApO{#Q
} ai?N!RX%H
catch(IOException e){e.printStackTrace ();} +e.w]\}
catch(Exception e){e.printStackTrace ();} 8QL=%Pv
HCkfw+gaV
V )UtU L
Utility.log(nFileLength); 3b#L*-
F&+qd`8J
%CnNu
return nFileLength; Qv'x+GVW]
} 4M]l~9;A
ZNDi;6e
m]}U!XT
//保存下载信息（文件指针位置） u>vvW|OB[
private void write_nPos() j+3rS
{ ?WqaT)l~
try{ :x5O1Zn/t
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]9_}S
output.writeInt(nStartPos.length); dHg[r|xC
for(int i=0;i<nStartPos.length;i++) Y-st2r[,
{ 4{vEW(
// output.writeLong(nPos); |N)),/R_
output.writeLong(fileSplitterFetch.nStartPos); fI<d&5&g
output.writeLong(fileSplitterFetch.nEndPos); ]91QZ~4a
} UU[z\^w| E
output.close(); zG/? wP"
} &Ruq8n<
catch(IOException e){e.printStackTrace ();} mvTp,^1
catch(Exception e){e.printStackTrace ();} !J!&JQ|
} _emW#*V
n53c}^
3HuGb^SNg
//读取保存的下载信息（文件指针位置） 6rD]6#D
private void read_nPos() nN-S5?X#
{ xsPt
try{ <HN{.p{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); olL? 6)gC
int nCount = input.readInt(); 1ZRkVHiz0
nStartPos = new long[nCount]; Q(q&(/
nEndPos = new long[nCount]; cPAR.h,b?
for(int i=0;i<nStartPos.length;i++) TXyiCS3
{ Px*<-t|R-
nStartPos = input.readLong(); bi",DKU{l
nEndPos = input.readLong(); |Ox='.oIb
} xYW&Mfka
input.close(); Y.tT#J^=
} zA.0Sm
catch(IOException e){e.printStackTrace ();} Q[q`)~|
catch(Exception e){e.printStackTrace ();} T*=*$%
} nSBhz
&dK!+
6@8z3JW.A
private void processErrorCode(int nErrorCode) U~"Y8g#qgy
{ XpE847!soL
System.err.println("Error Code : " + nErrorCode); Suo$wZ7J
} }P{Wk7#Jq
gGMQRRq
s0D4K
//停止文件下载 k 9z9{
public void siteStop() XQfmD;U
{ `=,emP&(H&
bStop = true; M;OMsRCVO
for(int i=0;i<nStartPos.length;i++) s/C'f4
fileSplitterFetch.splitterStop(); LGW_7&0<<
<m1v+cnqo
0%}*Zo(e+
} J>nBTY,_<
} GPL%8 YY
//负责部分文件的抓取 RB%y($
**FileSplitterFetch.java LGZa l&9AY
*/ $7g+/3Fu^
package NetFox; f38e(Q];m
ysp`(n=
ey4.Hj#T
import java.io.*; b l+g7g;
import java.net.*; +`{OOp=
5dE=M};v
+ Hv'u
public class FileSplitterFetch extends Thread { (1GU
v0E6i!D/
|K-`
String sURL; //File URL &{+0a[rN
long nStartPos; //File Snippet Start Position y5+%8#3
long nEndPos; //File Snippet End Position {Y Y,{H
int nThreadID; //Thread's ID 8,!Oup
boolean bDownOver = false; //Downing is over qz (x
boolean bStop = false; //Stop identical :|niFK4
FileAccessI fileAccessI = null; //File Access interface nQ_{IO8/6W
3z2 OW@zL$
6(4d3}F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *x;4::'Jn
{ :N$-SV
this.sURL = sURL; v}V[sIs}
this.nStartPos = nStart; nM b@ B
this.nEndPos = nEnd; l$EN7^%w
nThreadID = id; <9yh:1"X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u{\'/c7G
} m}=E$zPbO
"UNFB3
pb)8?1O|s
public void run() (?JdiY/
{ bDtb6hL
while(nStartPos < nEndPos && !bStop) ,%l}TSs
{ -,p=;t#(
ZcyGLg0I
7>F{.\Z
try{ +>vKI8g*RH
URL url = new URL(sURL); * zyik[o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9CeR^/i
httpConnection.setRequestProperty("User-Agent","NetFox"); 6:Z8d%Z
String sProperty = "bytes="+nStartPos+"-"; xSK#ovH2
httpConnection.setRequestProperty("RANGE",sProperty); ~tW~%]bs2Q
Utility.log(sProperty); mOn_#2=KF
q=BljSX
!@8i(!xb
InputStream input = httpConnection.getInputStream(); T+$H[&j
//logResponseHead(httpConnection); }F_c0zM
fZ7AGP
zN|k*}j1J
byte[] b = new byte[1024]; N~mr@rXC
int nRead; FC,=g`Q!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RLnL9)`W
{ !+^'Ej)z
nStartPos += fileAccessI.write(b,0,nRead); uu,F5<y[
//if(nThreadID == 1) ZqVbNIY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'OziP
} =huV(THU
.)!QsBU
;'uQBx}
Utility.log("Thread " + nThreadID + " is over!"); %sr- xE
bDownOver = true; Hn(1_I%zF
//nPos = fileAccessI.write (b,0,nRead); AO|9H`6U6F
} o5F:U4sG
catch(Exception e){e.printStackTrace ();} V\<2oG
} R54[U
} X(nyTR8
K=v:qY4Z
^Q$OzsEk
//打印回应的头信息 #T^2=7 w
public void logResponseHead(HttpURLConnection con) y-1e(:GF
{ *<($.c
for(int i=1;;i++) ^1bslCe
{ Kx]SiejJ
String header=con.getHeaderFieldKey(i); M[YFyM(
if(header!=null) A:r?#7 Ma
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~&73f7
Utility.log(header+" : "+con.getHeaderField(header)); "/i$_vl
else - Fbp!*. u
break; TD}<U8I8_
} 'YNdrvz
} 1" cv5U
1w^wa_qx
fj5g\m
public void splitterStop() X&qx4DL
{ !`Rh2g*o9
bStop = true; lZcNio
} UPfO;Z`hJ
s.}K?)mH
2(xC|
} U+)p'%f;
'Be'!9K*d
`)n4I:)2
/* Vi8A4
**FileAccess.java :/;/mHG]
*//文件访问(定位，写) EE!}$qOR
package NetFox; [!A[oK9i C
import java.io.*; :-k|jt
p%"dYH%]&0
|/*Pimk
public class FileAccessI implements Serializable{ 'kZ,:.v
xLz=)k[''
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -[V-f> :
RandomAccessFile oSavedFile; ^[tE^(|T
long nPos; p?:5U[KM
5:h[%3'bB
cqNK`3:.j
public FileAccessI() throws IOException ((k"*f2%
{ dq[h:kYm
this("",0); FLqN3D=yQ
} pSw/QO9
7C{ yNX#
*Y m?gCig
public FileAccessI(String sName,long nPos) throws IOException Dsg>~J'
{ 3yZmW$E.
oSavedFile = new RandomAccessFile(sName,"rw"); G21o@38e
this.nPos = nPos; yp.K-
oSavedFile.seek(nPos); `Z?wj@H1`
} ;<AcW.jx
EiW|+@1
JQ&t"`\k
public synchronized int write(byte[] b,int nStart,int nLen) 2d !'9mA
{ i<m(neX[H
int n = -1; Pd*[i7zhC
try{ I0)`tQ+
oSavedFile.write(b,nStart,nLen); w )R5P[b
n = nLen; JbMTULA
} $1an#~
catch(IOException e) k"(]V
{ %iN>4;T8
e.printStackTrace (); Z4j6z>qE
} ,BU;i%G&s
7~/cz_
%z><)7
return n; iQwQ5m!d &
} yGZsNd {a&
S(Yd.Sp
NB"S,\M0
} S\k<
e3?=1ZB
(jgk! 6
/* Ej(Jj\
**SiteInfoBean.java :HkBP90o
*/ +&Ld`d!n
package NetFox; c3A\~tHW
}htjT/Nm
dj0; tQ=C
public class SiteInfoBean { tMIYVHGy
vT'Bs;QR
!>8~R2
private String sSiteURL; //Site's URL RK>Pe3<
private String sFilePath; //Saved File's Path K7+yU3
private String sFileName; //Saved File's Name WSkGVQu
private int nSplitter; //Count of Splited Downloading File h+f>#O+:
CLb6XnkcA\
H",B[ YK
public SiteInfoBean() _'u]{X\k{J
{//nSplitter的缺省值为5 E$e7(D
//default value of nSplitter is 5 3FEJ 9ZyG
this("","","",5); b'H'QY
} RpHlq
I2ek`t]
&|>+LP@8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 24mdhT|
{ H"C'<(4*\
sSiteURL= sURL; 5,RUPaE
sFilePath = sPath; R?2sbK4Cz
sFileName = sName; GF'wDi}
this.nSplitter = nSpiltter; 'Ts:.
qS!r<'F3dP
)?L=o0
} `zwz
.J"N}
3dShznlf_*
public String getSSiteURL() fV(3RG
{ iHK~?qd}
return sSiteURL; qtGJJ#^,
} .1x04Np!
^rkKE dd
<#63tN9
public void setSSiteURL(String value) THA9OXP
{ hGRj
sSiteURL = value; XC4Z,,ah"
} ,g`%+s7u
c}x1-d8
YdY-Jg Xm
public String getSFilePath() )&DAbB!O
{ =BsV`p7rU
return sFilePath; CUA @CZ6{
} }2A6W%^>]
[&Xp]:M'D
p|4qkJK8
public void setSFilePath(String value) 97}]@xN=
{ ) "#'
sFilePath = value; [\uR3$j#
} g|=_@ pL
WA{igj@\
H#-3
public String getSFileName() I-7LT?r
{ .b:!qUE^
return sFileName; $|4C]Me (
} l?Y^3x}j
q>q:ZV
0bNvmZ$
public void setSFileName(String value) bm588UQ
{ +Qs]8*^?;
sFileName = value; >%JPgr/ 8
} NzRvbj]
jXcJ/g(X3
)n/%P4l
public int getNSplitter() QaX.Av
{ w-jElV
return nSplitter; 0MQ= Rt
} z(PUoV:?
h\m35'v!
Zw]`z*,yRA
public void setNSplitter(int nCount) 8WP>u8&
{ eh#37*-
nSplitter = nCount; FR(W.5[
} =O/Bte.
} vNv?trw
fF:57*ys
-F[8ZiZ
/* ^s,3*cAU
**Utility.java gmTBT#{6yH
*/ WxdQ^#AE
package NetFox; ;'!x
t@RYJmW
St=nf\P&F
public class Utility { jA? #!lx_
c=\tf~}^Ms
(5a73%>@
public Utility() MsB>3
{ 7GA8sK
Wj{lb_Rj
B|(g?
} ! VwU=5
Xo^8o0xi
//线程睡眠 AXfU$~
public static void sleep(int nSecond) 8(3(kZxS
{ iT@`dEZ.
try{ >WLPE6E
Thread.sleep(nSecond); |1tKQ0jg
} FU|brSt
catch(Exception e) npP C;KD
{ !U`&a=k
e.printStackTrace (); {N(qS'N
} (1/Sf&2i
} OhF55,[
DF%d/a{]
//日志 3)OZf{D[
public static void log(String sMsg) `CK~x=
{ uf(ayDE
System.err.println(sMsg); VA/2$5Wu
} 7KT*p&xm
On C)f
Pz]WT1J0
public static void log(int sMsg) yUoR6w
{ ;i{B,!#
System.err.println(sMsg); ,CE/o7.FG
} x"r0<RK
} u ExLj6
T+8Yd(:hX
?y>N&\pt2
/* g/?Vl2W
**TestMethod.java j*=!M# D
*/ @uSO~.7
package NetFox; Jcw^Z,
6#w>6g4V~R
ktu?-?#0,
public class TestMethod { RK# 6JfC3X
!E70e$Th
B`pBIUu
public TestMethod() ;W|kc</R*
{ ///xx/weblogic60b2_win.exe UhB+c
try{ ?7\V)$00(&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); UG1<Xfu|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \0@DOW22C
SiteFileFetch fileFetch = new SiteFileFetch(bean); =g% L$b<i
fileFetch.start(); 6:1`lsP
} tldT(E6
catch(Exception e){e.printStackTrace ();} h yrPu_
}_Bo:*9B-o
lH fZw})d
} gt4GN`-k
]aN9mT N
,@"yr>Q9#6
public static void main(String[] args) *i#2>=)
{ Zy0M\-Mn
new TestMethod(); ZbRRDXk!
} )1<0c@g=
} PW*Vfjf4
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