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)); qg/FI#r
} Dkx}}E:<
for(int i=0;i<nEndPos.length-1;i++) BCuoFw)
{ "L;@qCfhO
nEndPos = nStartPos[i+1]; po(pi|
} $NCR V:J
nEndPos[nEndPos.length-1] = nFileLength; 'd|!Hr<2
} BaWU[*
} *8_Dn}u?Jx
2+/r~LwbK
dW22v!
//启动子线程 >& 4):
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Eyz.^)r
for(int i=0;i<nStartPos.length;i++) RU=\eD
{ nLOK1@,4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X`3_ yeQc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gnkeJ}K
nStartPos,nEndPos,i); /i dI-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eso-{W,D
fileSplitterFetch.start(); ($!uBF-b
} 7n o6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $e2+O\.>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d!46`b$rd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Io"3wL)2
nEndPos = " + nFileLength); d>NO}MR
// fileSplitterFetch[nPos.length-1].start(); "iGQ1#6|d
sv&^sARN
y@,PTF
//等待子线程结束 q7rb3d
//int count = 0; en/h`h]h
//是否结束while循环 lo1bj*Y2
boolean breakWhile = false; \#]C !JQ
pY[b[ezb
YR? E z<p
while(!bStop) |h%HUau
{ eXD~L&s[
write_nPos(); 7W*a+^
Utility.sleep(500); XjCx`bX^<
breakWhile = true; 3~7!=s\v
EJ>rW(s
@/?i|!6
for(int i=0;i<nStartPos.length;i++) b`$qKO
{ B'Jf&v
if(!fileSplitterFetch.bDownOver) {* :^K\-
{ SSCs96
breakWhile = false; 0g6sGz=
break; OjAdY\ ]1
} 2@lGY_O!m
} !*L)v
if(breakWhile) $U.|
break; w;{Q)_A
OF={k[
pdR\Ne0P*
//count++; G[JWG
//if(count>4) N UvVhy]{
// siteStop(); #rF`Hk:
} _WvVF*Q"k
M)!"R [V
$./aKJ1B
System.err.println("文件下载结束！"); -.y1]4
} [|YvVA
catch(Exception e){e.printStackTrace ();} SD:D8"8
} Y#Q!mbp
[OTn>/W'
cD6^7QF
//获得文件长度 W7'<Jom|?
public long getFileSize() [*5]NNB
{ 8B &EH+
int nFileLength = -1; ^"D^D`$@
try{ 6WT3-@d
URL url = new URL(siteInfoBean.getSSiteURL()); TE$6=;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OJ"./*H
httpConnection.setRequestProperty("User-Agent","NetFox"); e ><0crb
7l$ u.[
:N_]*>
int responseCode=httpConnection.getResponseCode(); >qOG^{&x
if(responseCode>=400) Y2XxfZj
{ AEaN7[PQx|
processErrorCode(responseCode); |nWEuKHy
return -2; //-2 represent access is error qPD(D{,f$
} qbD 7\%
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A.("jb@I
String sHeader; ye=4<b_
A-:k4] {%P
O1c:X7lHc
for(int i=1;;i++) HV)aVkr/&
{ I/O/*^T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =f y|Dm74
//Utility.log(in.readLine()); &PRoT#,
sHeader=httpConnection.getHeaderFieldKey(i); lH`TF_
if(sHeader!=null) h2T\%V_j
{ J<+f7L
if(sHeader.equals("Content-Length")) /{`"X_.o
{ !L9OJ1F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s5{=lP
break; {pH#zs4Y
} *E/ Mf
} ~WTkX(\
else &K60n6q{aQ
break; _qf39fM;\
} B7[d^Y60B
} wpYk`Lr
catch(IOException e){e.printStackTrace ();} -JF^`hBD-
catch(Exception e){e.printStackTrace ();} 5N$XY@
aIFlNS,y
5v)bs\x6
Utility.log(nFileLength); o ?vGI=
Ms,MXJtH
dt:$:,"
return nFileLength; nOL.%
} r9&m^,U
_3@5@1[s
YmaS,Q-
//保存下载信息（文件指针位置） Nz.X$zUmY
private void write_nPos() Rr%x;-
{ m!Z<\2OP
try{ O 1z0dHa
output = new DataOutputStream(new FileOutputStream(tmpFile)); =xIZJ8e
output.writeInt(nStartPos.length); z/xPI)R[
for(int i=0;i<nStartPos.length;i++) j;y~vX b
{ xmcZN3 ){+
// output.writeLong(nPos); vio>P-2Eho
output.writeLong(fileSplitterFetch.nStartPos); Y2QX<
output.writeLong(fileSplitterFetch.nEndPos); zaHZ5%{LQD
} b{ xlW }S
output.close(); s+lBai*#
} ebI2gEu;a
catch(IOException e){e.printStackTrace ();} >*h+N? m
catch(Exception e){e.printStackTrace ();} `8W HVC$
} Rv9jLH
9D1WUUa
30uPDDvar
//读取保存的下载信息（文件指针位置） #O}}pF
private void read_nPos() 6 Ln~b<I
{ T9Q3I
try{ \\<=J[R.M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &Q~W{.
int nCount = input.readInt(); D?1fY!C:r
nStartPos = new long[nCount]; w'(/dr
nEndPos = new long[nCount]; Xj/z),
for(int i=0;i<nStartPos.length;i++) *"8Ls0!
{ n_km]~
nStartPos = input.readLong(); ? /z[Jx.
nEndPos = input.readLong(); vHpw?(]
} xt5/`C
input.close(); `T[@-
} i>YQ<A1
catch(IOException e){e.printStackTrace ();} K#wA ;
catch(Exception e){e.printStackTrace ();} }psRgF
} e9h@G#
H"l4b4)N\
K'r;#I|"J
private void processErrorCode(int nErrorCode) WqNXE)'
{ %/y=_G
System.err.println("Error Code : " + nErrorCode); #mu L-V
} (~^fx\-S
2uE<mjCt-r
f(m,!
//停止文件下载 43AzNXWF8
public void siteStop() v{a%TA9-
{ Q!1;xw~
bStop = true; Z{0BH{23
for(int i=0;i<nStartPos.length;i++) f+ceL'fr
fileSplitterFetch.splitterStop(); 8-nf4=ll
c("|xe
oM~y8O
} \s5Uvws
} |g3:+&
//负责部分文件的抓取 E:pk'G0bZ
**FileSplitterFetch.java :9UgERjra
*/ #%p44%W
package NetFox; c,2& -T}
<(lA CH
=WY'n l'
import java.io.*; H/O.h@E4X
import java.net.*; Kk8}m;
8~o']B;lJ
7a'yO+7-)
public class FileSplitterFetch extends Thread { `sYFQ+D#O
M@A3+v%K
F$?Ab\#B
String sURL; //File URL ;yt6Yp.6e
long nStartPos; //File Snippet Start Position w'H'o!*/
long nEndPos; //File Snippet End Position l:V R8g[
int nThreadID; //Thread's ID 0!|d .jZI
boolean bDownOver = false; //Downing is over 0 jth}\9
boolean bStop = false; //Stop identical 46A sD
FileAccessI fileAccessI = null; //File Access interface SraZxuPg>
OT])t<TF6
+{I_%SsG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `uMEK>b
{ Y7}>yC/GY
this.sURL = sURL; s7 "xDDV
this.nStartPos = nStart; x"12$79=
this.nEndPos = nEnd; Wm}c-GD
nThreadID = id; V^2_]VFj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'K,\
} t_3j_`
1(?4*v@B
^&eF916H
public void run() ,@ 8+%KqG
{ SN{+ Pk
while(nStartPos < nEndPos && !bStop) wGArR7r
{ LlQsc{Ddf
6L<:>55
3^o(\=-JX
try{ k6Kc{kY
URL url = new URL(sURL); =:WZV8@%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8v"rM >[
httpConnection.setRequestProperty("User-Agent","NetFox"); ebk>e*
String sProperty = "bytes="+nStartPos+"-"; EU?qLj':
httpConnection.setRequestProperty("RANGE",sProperty); {[oNUzcd
Utility.log(sProperty); qk(Eyp
\3 SY2g8+
?gE=hh
InputStream input = httpConnection.getInputStream(); RPz[3y
//logResponseHead(httpConnection); ~`OX}h/Z
?.?)5 &4
e%\^V\L
byte[] b = new byte[1024]; Pp8S\%z~h
int nRead; U6]#RxH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;t&q|}x"
{ l76=6Vtb
nStartPos += fileAccessI.write(b,0,nRead); Xsq@E#@S
//if(nThreadID == 1) F(G..XJQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0WUBj:@g
} k)p`x"To
B@,r8)D
?*fa5=ql
Utility.log("Thread " + nThreadID + " is over!"); Ww]$zd-bo
bDownOver = true; ;'"'|} xn
//nPos = fileAccessI.write (b,0,nRead); vhrf89-q
} <>] DcA
catch(Exception e){e.printStackTrace ();} uk):z$x
} HbKE;N
} +MoUh'/u
hhTtxC<:
E=sh^Q(A
//打印回应的头信息 TjW!-s?S
public void logResponseHead(HttpURLConnection con) `fBQ?[05.
{ 5PeS/%uT@
for(int i=1;;i++) s.2f'i+
{ 2@|`Ugjptl
String header=con.getHeaderFieldKey(i); MpCPY"WLL
if(header!=null) nQF&^1n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Qd}n4KF\
Utility.log(header+" : "+con.getHeaderField(header)); @Kpm&vd(
else ;vH2r~
break; 0]DOiA
} 8?yIixhw
} .hT>a<
O =Z}DGa+
.a%6A#<X
public void splitterStop() *[Hp&6f
{ m%HT)`>bg
bStop = true; p*g Fr hm
} 02J/=AC5
t;8)M$ p
DzZF*ylQ5P
} uF7vba$
t7Q$
Y)rK'OY'
/* R3>q]
**FileAccess.java }LUvh
*//文件访问(定位，写) F&Md+2
package NetFox; xIM,0xM2
import java.io.*; EmNVQ1w
Za|7gt];l
tr0b#4
public class FileAccessI implements Serializable{ x@-K
5aQ)qUgAW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ua1&eCZi
RandomAccessFile oSavedFile; 'P.y?
long nPos; -)V0D,r$[
BZeEZ2"
pzF_g-B
public FileAccessI() throws IOException T\6Qr$t
{ X`8<;l
this("",0); A(y6]E!
} 1-kuK<KR
<5zR-UA>
oC&}lp)q
public FileAccessI(String sName,long nPos) throws IOException omfX2Oa2
{ A*h8 o9M
oSavedFile = new RandomAccessFile(sName,"rw"); >.?yz
this.nPos = nPos; r_7%|T8
oSavedFile.seek(nPos); vXJs.)D7
} !wYN",R-
?JuJu1
CsR[@&n'
public synchronized int write(byte[] b,int nStart,int nLen) nW=6nCyvo
{ x;mw?B[
int n = -1; 9{pT)(Wnb
try{ 8lF9LZ8
oSavedFile.write(b,nStart,nLen); }QE.|.fA1
n = nLen; ;}B=g/C
} m$8siF{<q
catch(IOException e) #qd!_oN
{ >tg)F|@
e.printStackTrace (); _H| )g*]t
} `m 5\
Es=G' au
[@K'}\U^+
return n; H1N@E}>|
} (kL"*y/"p
4 ]oe`yx
x?i wtZ@
} (B#FLoK
R@\fqNq
_S_,rTf&
/* F8%^Ed~@
**SiteInfoBean.java xF_u:}7`
*/ IOHWb&N6
package NetFox; XpAJP++
z_c-1iXCW
$WYt`U;*lj
public class SiteInfoBean { ekx(i QA
]}`t~#Irz
-jjB2xP
private String sSiteURL; //Site's URL 8:Hh;nl
private String sFilePath; //Saved File's Path 5OdsT-y
private String sFileName; //Saved File's Name i4YskhT
private int nSplitter; //Count of Splited Downloading File ruaZ(R[
b:(+d"S
H{cOkuy
public SiteInfoBean() FK BRJ5O
{//nSplitter的缺省值为5 p\zqZ=s
//default value of nSplitter is 5 9/"&6,
this("","","",5); A1zRzg4I
} eC/{c1C
6*,55,y
pj%]t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q/?*|4I
{ BB}WfA
sSiteURL= sURL; @3n!5XM{EE
sFilePath = sPath; nOC\ =<Nsg
sFileName = sName; V lZ+x)E
this.nSplitter = nSpiltter; B7Ket8<J
5bb#{?2i
5Sl"1HL
} -zECxHjx
CH7a4qL`
AMrYT+1
public String getSSiteURL() PTHxvml
{ cc${[yj)
return sSiteURL; \d:Q%S
} .#y#u={{l
C b'|
\BBs;z[/
public void setSSiteURL(String value) kQI'kL8>
{ %@QxU-k_
sSiteURL = value; QFTiE1mGH
} iv`G}.Bo
}w)}=WmD
a;$V;3C{b&
public String getSFilePath() 2IJniS=[>
{ Xau%v5r
return sFilePath; o?]Q&,tO
} Q`i@['?p
:%sG'_d
oDS7do
public void setSFilePath(String value) k3&68+
{ A8ViJ
sFilePath = value; +At[[
} *6JA&zj0B
3MX#}_7A
pg5W`4-F
public String getSFileName() {]Mwuqn
{ uP4yJ/]
return sFileName; a@g <cl7a,
} 7 \xCNOKh
.XpuD,^;@
Xg.Lo2s
public void setSFileName(String value) W. d',4)
{ [fCnq
sFileName = value; mBIksts5h
} P^o@x,V!&
U/FysN_N!
54{E&QvL8o
public int getNSplitter() UR'v;V&Cb\
{ koB'Zp/FaY
return nSplitter; 9T;>gm
} dLqBu~*
t=lDN'\P
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public void setNSplitter(int nCount) 5_A*IC]
{ N/>:})dav
nSplitter = nCount; (x% 4*
} AQ FnS&Y
} b~ )@e9
q1HJ_y
.3) 27Cjw
/* Bor_(eL^
**Utility.java %,$xmoj9O]
*/ = y^5PjN
package NetFox; C}9GrIi
UZsvYy?
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public class Utility { AyUw
;E{jn4B'
xA^E+f:W_
public Utility() 7oZPb
{ /0>'ZzjV,
C-ORI}o
dU_;2d$
} FD!8o
6yYjZ<
//线程睡眠 >/RFff]Fh0
public static void sleep(int nSecond) E el*P M
{ M8:i]
try{ D,*|:i
Thread.sleep(nSecond); [$K8y&\L
} zT}vaU6
catch(Exception e) 1mHS -oI9J
{ }.s%J\ckx
e.printStackTrace (); @gqZiFM)
} W4.w
} NsS;d^%I
h}nS&.
//日志 \{Q_\s&)
public static void log(String sMsg) Z[&FIG%tV
{ P )oNNY6}
System.err.println(sMsg); #Rfcp!
} #|+4`Gf^
tf54EIy5Y
Q"NZE
public static void log(int sMsg) f.j<VKF}
{ A ?tna6W:
System.err.println(sMsg); *BrGh
} !\VEUF,K?
} s%rmfIp"
JXRU9`3)A
Y6Y"fb%K
/* C(h<s e?
**TestMethod.java i@D4bd9lR
*/ #?\(l%
package NetFox; 7MZH'nO
|_g7k2oLY
T9J&^I
public class TestMethod { E;`^`T40
lq.]@zlSO
k(7Q\JKE
public TestMethod() H_XspiB@
{ ///xx/weblogic60b2_win.exe %H{;wVjK
try{ }oiNgs/N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I.Catm2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z3 ^_C`(F
SiteFileFetch fileFetch = new SiteFileFetch(bean); YH+(N
fileFetch.start(); Uu*iL< `
} &Qv HjjQ?u
catch(Exception e){e.printStackTrace ();} (#6Fg|f4Y
%${$P+a`D
/Q)I5sL@E
} `<~=6H
~}{_/8'5
PP\ bDEPy
public static void main(String[] args) wA7\K~fHV
{ #X1a v
new TestMethod(); 7. $wK.
} >}+R+''nR
} :81d~f7
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