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)); "k'P #v{f
} lc8zF5
for(int i=0;i<nEndPos.length-1;i++) 8EBy5X}US
{ dtDT^~
nEndPos = nStartPos[i+1]; zHu w[
} '] $mt
nEndPos[nEndPos.length-1] = nFileLength; FIEA'kUy
} OKO+(>AQ
} |K,[[D<R
snm1EPj
u#^~([I
//启动子线程 $FM:8^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A]_5O8<buW
for(int i=0;i<nStartPos.length;i++) ~qu}<u)P
{ /ho7O/aAa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;T,`m^@zf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A/A;'9
nStartPos,nEndPos,i); +{dJGPoY]p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E$1P H)
fileSplitterFetch.start(); |ycN)zuE
} H b}(.`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N6thbH@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z1vSt[s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y-fDYMm
nEndPos = " + nFileLength); Y4j%K~lsY
// fileSplitterFetch[nPos.length-1].start(); sG K7Uy
hvo7T@*'
u`~,`z^{n
//等待子线程结束 L2}p<?f
//int count = 0; n{8v^x
//是否结束while循环 _p^&]eQ+k#
boolean breakWhile = false; agUdPl$e\
.jK,6't^
>tQ$V<YB
while(!bStop) 57`*5X
{ h(MNH6B1
write_nPos(); `\Ye:$q
Utility.sleep(500); <Dq7^,}#
breakWhile = true; {wwkbc*
e.l3xwt>$
t}x^*I$*
for(int i=0;i<nStartPos.length;i++) mVVL[z2+
{ sOb=+u$$9
if(!fileSplitterFetch.bDownOver) 7:$zSj#y
{ &++tp5
breakWhile = false; qtYVX:M@,
break; yD:}&!\}
} ]7:*A7/!.
} t=BXuFiu
if(breakWhile) -hpC8YS
break; )gPkL r
!'f.g|a
,%4~ulKMn
//count++; W)p?cK`
//if(count>4) <4,LTB]9-
// siteStop(); g7@.Fa.u'!
} 2{oU5e
"^&Te%x_b
]GH_;
System.err.println("文件下载结束！"); *h4x`luJ
} E*G{V j
catch(Exception e){e.printStackTrace ();} ]3&BLq
} /P koqA,
fj:q_P67o
D\-D~G]x
//获得文件长度 >#EOCo
public long getFileSize() +5xk6RP
{ I6lWB(H!u
int nFileLength = -1; (>M? iB
try{ Gq0Q}[53
URL url = new URL(siteInfoBean.getSSiteURL()); CEl9/"0s6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _4-UM2o;
httpConnection.setRequestProperty("User-Agent","NetFox"); ;!Q}g19C
s^zX9IVnp
3Xl!Z^W
int responseCode=httpConnection.getResponseCode(); :{'%I#k2
if(responseCode>=400) .X;DI<K
{ 7L !$hk
processErrorCode(responseCode); ;+(EmD:Q
return -2; //-2 represent access is error .g8db d
} k#DMd9
mr<camL5
_,bDv`>Ra
String sHeader; C<yjGtVD
G-Dc(QhU&
b 67l\L
for(int i=1;;i++) l,@rB+u
{ #Zj3SfU~`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .ovG_O
//Utility.log(in.readLine()); 4ZCD@C
sHeader=httpConnection.getHeaderFieldKey(i); >&D}^TMYY
if(sHeader!=null) Xcw6mpLt
{ V8-*dE
if(sHeader.equals("Content-Length")) Q~zs]{\
{ `FHKQS5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t*(buAx
break; aM!%EaT
} "U o~fJ
} BVe c
else Y"UB\_=
break; u=f}t=3
} D V=xqC6}
} |$G|M=*LN
catch(IOException e){e.printStackTrace ();} =l+~}/7'Z
catch(Exception e){e.printStackTrace ();} D0VbD" y
6`V~cVu
d$#DXLA\P
Utility.log(nFileLength); g\Akf
SK t&BnW
s_4y^w]aX
return nFileLength; E:ti]$$
} ),5|Ves;t[
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&at>sQ'
//保存下载信息（文件指针位置） ]%eyrbU
private void write_nPos() %[WOQ.Sh
{ Bhg,P.7
try{ kX "*kD
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?G<.W[3
output.writeInt(nStartPos.length); HC(7,3
for(int i=0;i<nStartPos.length;i++) <Wa7$hF
{ \Y^GA;AMQQ
// output.writeLong(nPos); Ngw/H)<c
output.writeLong(fileSplitterFetch.nStartPos); ~U+W4%f8
output.writeLong(fileSplitterFetch.nEndPos); e!oL!Zg
} ]*TW%mY
output.close(); |"i"8~/@<
} 0@/C5 v
catch(IOException e){e.printStackTrace ();} nNpXkI:
catch(Exception e){e.printStackTrace ();} 'tn-o
} UoOxGo
g66x;2Q
EWK?vs
//读取保存的下载信息（文件指针位置） Zr|z!S?aSC
private void read_nPos() &h'NC%"v
{ M~Ph/
try{ $VnPs!a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qc"PTv0q
int nCount = input.readInt(); wuKr9W9Xa
nStartPos = new long[nCount]; dLtmG:II
nEndPos = new long[nCount]; M@<r8M]G
for(int i=0;i<nStartPos.length;i++) bBgyLyg
{ {4YD_$4W
nStartPos = input.readLong(); e {805^X}
nEndPos = input.readLong(); X3R:^ff\
} DyM<aT
input.close(); P0ZY;/e5h
} DSL3+%KF#
catch(IOException e){e.printStackTrace ();} Xz\X 8I
catch(Exception e){e.printStackTrace ();} Rv Uw,=
} Wp(Rw4j
KSQ*HO)5
Ws;X;7tS
private void processErrorCode(int nErrorCode) 8c5=Px2\
{ +@qIDUiF3
System.err.println("Error Code : " + nErrorCode); D8\9nHUD`
} 0;tu}]jnN
>Y=qSg>Ik
$/"QYSF
//停止文件下载 _|wnmeL*
public void siteStop() Eu2(#z 6eW
{ 04#<qd&ob@
bStop = true; Tl L\&n.$
for(int i=0;i<nStartPos.length;i++) j|%>NB ):
fileSplitterFetch.splitterStop(); 4azqH;i
lQ!(lPh
~ugH2jiB
} >oL| nwn
} VU;98
//负责部分文件的抓取 5`Y>!| Ab
**FileSplitterFetch.java {Lugdf'
*/ ?eDZ-u9)
package NetFox; C=x70Y/
k|3hs('y|
cQrXrij;!
import java.io.*; 349BQ5ND
import java.net.*; 9yWSlbPr]
C@!bd+'
m*vz
public class FileSplitterFetch extends Thread { V<Co!2S
Q=t_m(:0
oQK,#>rv
String sURL; //File URL (je`sV
long nStartPos; //File Snippet Start Position j9f[){m`
long nEndPos; //File Snippet End Position 9gac7(2`)
int nThreadID; //Thread's ID He1~27+99
boolean bDownOver = false; //Downing is over F0ylJ /E
boolean bStop = false; //Stop identical 5,9cD`WR^
FileAccessI fileAccessI = null; //File Access interface \]0+J
=}'7}0M_=
2?kVbF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R{UZCFZ
{ Zx^R-9
this.sURL = sURL; cp2a @
this.nStartPos = nStart; *0x!C8*`Xe
this.nEndPos = nEnd; =55V<VI
nThreadID = id; e, }{$HStZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d#|%h] 6
} G6pR?K+
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CPcB17!
public void run() RmJ|g<
{ J~)JsAXAI
while(nStartPos < nEndPos && !bStop) ^f9>tI{
{ `$XgfMBf |
{m/KD 'b_
ce7$# #f
try{ Q}|0
URL url = new URL(sURL); 8@r>`c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !im%t9
httpConnection.setRequestProperty("User-Agent","NetFox"); wU-Cb<^
String sProperty = "bytes="+nStartPos+"-"; ?d_vD@+\
httpConnection.setRequestProperty("RANGE",sProperty); q@i.4>x
Utility.log(sProperty); 6W9lKD_i
/$^SiE+N
]l^"A~va
InputStream input = httpConnection.getInputStream(); zqxN/H]z
//logResponseHead(httpConnection); <SiJA`(7
Lw`}o`D
uTvf[%EHW
byte[] b = new byte[1024]; 0u bf]Z
int nRead; SK5__Ix
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zvwv7JtB
{ :PNhX2F
nStartPos += fileAccessI.write(b,0,nRead); vHN/~k#
//if(nThreadID == 1) #g~]2x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zz #IY'dwT
} FpZ5@
+de5y]1H,|
.J?RaH{i
Utility.log("Thread " + nThreadID + " is over!"); .&.L@CRH
bDownOver = true; x\pygzQ/
//nPos = fileAccessI.write (b,0,nRead); :=\`P
} d?><+!a
catch(Exception e){e.printStackTrace ();} |nY+Nen7
} ~?B\+6<V
} #J~xKyJi'
$]MOAj"LH
U04)XfO;]
//打印回应的头信息 !,{-q)'D
public void logResponseHead(HttpURLConnection con) -BH T'zq1S
{ \~.elKw<U
for(int i=1;;i++) n<Ki.;-ZE
{ @%!Gj{
String header=con.getHeaderFieldKey(i); Y#FSU#a$<
if(header!=null) z8 K#G%,:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -^t&U] g
Utility.log(header+" : "+con.getHeaderField(header)); 06I(01M1
else 6>b'g ~I
break; uzL|yxt
} zLg_0r*h1
} g_?bWm4br
,irc=0M(
JC9OL.Ob
public void splitterStop() :@S=0|:j
{ 02C;
bStop = true; A+VzpJ~
} ^+Njz{rpG
z5W;-sCz
J7k=5Fqej;
} zwK$ q=-:
le2 v"Y
-l{ wB"
/* h([qq<Lzs
**FileAccess.java \3whM6tK
*//文件访问(定位，写) 0gr#<(
package NetFox; c[EG cY={
import java.io.*; h8P_/.+g|V
*-gmWATC6
RY*yj&?w[
public class FileAccessI implements Serializable{ e r"gPW
`3.bux~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2G$-:4B
RandomAccessFile oSavedFile; 9HAK
long nPos; EHm:&w
Z$S0X$q}
B|SX?X
public FileAccessI() throws IOException E#n:d9WA:
{ f0g&=k{OD
this("",0); \8`^QgV`@
} kp*BAQ
H}lbF0`
aq8mD^j-&
public FileAccessI(String sName,long nPos) throws IOException cd$,,
{ Q#Xa]A-
oSavedFile = new RandomAccessFile(sName,"rw"); 94.M8
this.nPos = nPos; z_a7HCG2
oSavedFile.seek(nPos); i>;6Z s>S
} C12y_E8Un
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jxnb<!|?H@
public synchronized int write(byte[] b,int nStart,int nLen) r8!M8Sc
{ +N!/>w]n
int n = -1; |sDp>..
try{ #uuNH(
oSavedFile.write(b,nStart,nLen); #}xPOz7:
n = nLen; rH[Eh8j,
} A{Q~@1
catch(IOException e) #b{;)C fL
{ 1 w9Aoc
e.printStackTrace (); i(kr#XsU
} 42 Sk`
(ce"ED`1
v9Ez0 :)
return n; bM $WU?Z
} #4!6pMW(&7
0WAOA6 _x
BF]+fs`
} 7s1LK/R|u
NjSjE_S2B8
Fprhu;h
/* 6 i]B8Ziq{
**SiteInfoBean.java #^q@ra
*/ b!g8NG
package NetFox; I)4NCjcCw
m ,TYF
7,3v,N|
public class SiteInfoBean { IF|%.%I$!U
KT8]/T`U
&qZ:"k
private String sSiteURL; //Site's URL @fSqGsSk
private String sFilePath; //Saved File's Path ,YmTx
private String sFileName; //Saved File's Name )X-TJ+d
private int nSplitter; //Count of Splited Downloading File mOx>p"n
">S.~'ds
+6x:+9S
public SiteInfoBean() ^os|yRzV*M
{//nSplitter的缺省值为5 ow,=M%x"0
//default value of nSplitter is 5 +#ANc;2g
this("","","",5); ;,:w%.
} LzkwgcR
U`ELd:
D~%h3HM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pw1&WP&?3
{ {NV=k%MTmi
sSiteURL= sURL; -Tr*G4
sFilePath = sPath; Q?W}]RW
sFileName = sName; 1FmVx
this.nSplitter = nSpiltter; 5K?%Eo72!=
+)TOcxF%
yy|F6Pq3`
} AN-;*n<'
@KC;"u'C
R8R,!3 N
public String getSSiteURL() <4P"1#nHQ+
{ \+sP<'~M
return sSiteURL; :KJZo,\
} N^K@$bs4^
Hsz).u
'} LAZQ"
public void setSSiteURL(String value) e5fzV.'5
{ $9O%,U@
sSiteURL = value; :[7.YQ
} GFtE0IQ
L<TL6
_M7NL^B&
public String getSFilePath() qW:\6aEG
{ &sJ%ur+G
return sFilePath; d512Y[ R
} z[ ml;?
J2~oIe2!+
"+J[7p}`@
public void setSFilePath(String value) I%31MU9
{ pwO U6A!
sFilePath = value; [\e2 ID;
} G=%SMl>[
mmrz:_
>vY5%%}
public String getSFileName() j /=4f�
{ .[4Dvt|>6
return sFileName; F^|4nBd*ub
} au 5qbP
>0qe*4n|M
xiG_l-2l
public void setSFileName(String value) 96 !e:TU
{ -|~tZuf
sFileName = value; \4|o5,+(@
} }H<87zH
|VD}:
)$e_CJ}9e
public int getNSplitter() 7cJh^M
{ w(Hio-l=
return nSplitter; 42mZ.,<
} uKocEWB=/F
H '(Ky
Bys_8x}
public void setNSplitter(int nCount) <rpXhcR
{ \zPcnDB
nSplitter = nCount; /{d5$(Y"
} ==pGRauq
} 1#<KZN =$
VaRP+J}UA.
N/&t)7
/* 41V}6+$g
**Utility.java +Qe&#"O0
*/ Iz[T.$9
package NetFox; THbV],RhJ
q!P{a^Fnc
qKd&d
public class Utility { @"=wn:O+
Lk~aMbw#
}\Mmp+<
public Utility() >'X[*:Cx
{ o|BEY3|
To"J>:l
hO@VYO
} 7D%}(pX
ayQB@2%
//线程睡眠 ;K9rE3
public static void sleep(int nSecond) 1Xi.OGl
{ zn@yt%PCV
try{ +(|6Wv
Thread.sleep(nSecond); JxM[LvVi
} cc^[u+
catch(Exception e) $m-rn'Q
{ h!L6NS_Q,
e.printStackTrace (); zU)Ib<$
} 4D-4BxN*
} H_CX5=Nq^
nmZJ%n
//日志 y`OL^D4
public static void log(String sMsg) nwm1YPs%v]
{ )6 _+
System.err.println(sMsg); 4/tp-dBip
} PV_q=70%T
w_hGWpm
oG_-a(N
public static void log(int sMsg) xiW;Y{kZ
{ s;;"^5B.
System.err.println(sMsg); T$ )dc^
} _v9P0W^.7
} ZRd,V~iz
V@"Y"}4n4
Z1gZn)7
/* =7U_ jDME
**TestMethod.java VTt{0 ~
*/ QP{V
package NetFox; +$F_7Hx
ny]R,D0
,9C~%c0Pw
public class TestMethod { C<.Ny,U
"/zIsn7
=#"ZO
public TestMethod() `bdCom
{ ///xx/weblogic60b2_win.exe Dr!g$,9
try{ ?U`~,oI0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RN%*3{-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s@ ~Y!A
SiteFileFetch fileFetch = new SiteFileFetch(bean); *"pf3x6
fileFetch.start(); #H@rb
} H?(I-vO
catch(Exception e){e.printStackTrace ();} &7YTz3aj
W_E0+
{|kEGq~aE
} o=1M<dL
6?3f+=e"~!
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public static void main(String[] args) `;9Z?]}`
{ 1%nE
new TestMethod(); FesXY856E
} jd]YKaI
} x]Nk T
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