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)); Tw7]
} lF_"{dS_6(
for(int i=0;i<nEndPos.length-1;i++) -QwH|
{ px*1 3"
nEndPos = nStartPos[i+1]; XDHi4i47`o
} 050,S`%<g8
nEndPos[nEndPos.length-1] = nFileLength; tHAe
} gJCZ9{Nl
} }8POm#
lB0`|UEb (
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//启动子线程 ~d].<Be
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i(_A;TT6
for(int i=0;i<nStartPos.length;i++) 8NiR3*1
{ tJybR"NQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h[&"KA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `<7!Rh,tS^
nStartPos,nEndPos,i); Ij$C@hH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T@Y, 7ccpd
fileSplitterFetch.start(); yYaoA/0
} G[`1Yw$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o+B)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @Ns[qn;9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kY @(-
nEndPos = " + nFileLength); L7d1)mV
// fileSplitterFetch[nPos.length-1].start(); 0{g*\W*+~
X6",Xr!{
1`YU9?
//等待子线程结束 Z %Ozzp/
//int count = 0; DzQ
//是否结束while循环 </WeB3#6
boolean breakWhile = false; xDGS`o_w_
Fs].Fa
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while(!bStop) N0.|Mb"?t
{ 4l+!Z,b
write_nPos(); R(`:~@3\6
Utility.sleep(500); 15,JD
breakWhile = true; '3Lu_]I-
.w;kB}$YC
;8eKAh
for(int i=0;i<nStartPos.length;i++) IO:*F0
{ h%krA<G9
if(!fileSplitterFetch.bDownOver) w4vV#C4X
{ Rd&DH_<+^
breakWhile = false; BBRL_6
break; xC,x_:R`
} bh<;px-
} Vv45w#w;
if(breakWhile) !t^DN\\#
break; e=WjFnK[x7
FO5a<6
REU,"
//count++; 3f] ;y<Km
//if(count>4) pK@=]K~l0
// siteStop(); USEb} M`
} 0z8?6~M;<
Jsysk $R
L23}{P
System.err.println("文件下载结束！"); w?8SQI,~X
} ;~EQS.Qp
catch(Exception e){e.printStackTrace ();} mAtqF %V
} EU%,tp
^>?=L\[
!:^q_q4
//获得文件长度 %'yrIR
public long getFileSize() <;6{R#Tuh
{ {]< G=]'
int nFileLength = -1; 8o$rF7.-
try{ eHuJFM
URL url = new URL(siteInfoBean.getSSiteURL()); Bchv1KF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I I+y
httpConnection.setRequestProperty("User-Agent","NetFox"); l6ym <V(1p
;^5k_\
yGdX>h
int responseCode=httpConnection.getResponseCode(); Zgo~"G
if(responseCode>=400) IHni1
{ A~2)ZdAN
processErrorCode(responseCode); wQSye*ec
return -2; //-2 represent access is error #GE]]7:Na
} Q$c6l[(g
;:fW]5"R
rG}e\ziKuj
String sHeader; FfdB%
6 Rl[M+Q
[OW <<6
for(int i=1;;i++) Do/R.Mgy*
{ YV<y-,Io
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |oi+|r
//Utility.log(in.readLine()); #wI}93E
sHeader=httpConnection.getHeaderFieldKey(i); ?T/]w-q>
if(sHeader!=null) _x!idf
{ a%T`c/C
if(sHeader.equals("Content-Length")) #;]#NqFX
{ STp9Gh-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RpQeQM=
break; vR!+ 8sy$
} P>VoA
} Aqmpo3P[+
else hMa;\k
break; Y~WdN<g
} %_ibe
} jYHnJ}<
catch(IOException e){e.printStackTrace ();} *nCA6i
catch(Exception e){e.printStackTrace ();} QB*,+u4
i6WH^IQM
% i4 5
Utility.log(nFileLength); 2.D2 o
wq$$. .E
tk&AZb,sP
return nFileLength; ;xZ+1zmL0
} _MBhwNBxZ
{p +&Q|
)G/bP!^+(
//保存下载信息（文件指针位置） xB *b7-a
private void write_nPos() `tkoS
{ gQy%T]
try{ C!j3@EZ$
output = new DataOutputStream(new FileOutputStream(tmpFile)); "do5@$p|
output.writeInt(nStartPos.length); 3iCe5VF
for(int i=0;i<nStartPos.length;i++) S,c{LTL
{ 42NfD/"g+s
// output.writeLong(nPos); U.e!:f4{
output.writeLong(fileSplitterFetch.nStartPos); --K)7
output.writeLong(fileSplitterFetch.nEndPos); !l (Vk
} T$5wH )<
output.close(); L4>14D\
} 9>)b6)J D
catch(IOException e){e.printStackTrace ();} ^kKLi
catch(Exception e){e.printStackTrace ();} )9YDNVo*-
} ZnEgU}g<2
(Q*q#U
1l,fK)z
//读取保存的下载信息（文件指针位置） OS(`H5D
private void read_nPos() .z>/A/&+
{ B\J[O5},
try{ j&8YE7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6}^x#9\
int nCount = input.readInt(); y2A\7&7
nStartPos = new long[nCount]; ]9oj,k
nEndPos = new long[nCount]; >C0B!MT?3%
for(int i=0;i<nStartPos.length;i++) 16iTE-J_
{ UPhO=G
nStartPos = input.readLong(); *k{Llq
nEndPos = input.readLong(); h`&TDB2
} Kxsd@^E
input.close(); zg2d}"dV
} aTvyzr1
catch(IOException e){e.printStackTrace ();} oGcgd$%ZB
catch(Exception e){e.printStackTrace ();} _Xf1FzF+a
} Y&6jFT_
N[_T3(
7{#p'.nc5
private void processErrorCode(int nErrorCode) b~gq8,Fatb
{ ynsYU(
System.err.println("Error Code : " + nErrorCode); TGJz[Ny
} ,}t%7I
ug9Ja)1|
;jzJ6~<
//停止文件下载 K*@?BE
public void siteStop() Q9bnOvKe|
{ xA3_W
bStop = true; n!4}Hwz!
for(int i=0;i<nStartPos.length;i++) n{?Du
fileSplitterFetch.splitterStop(); V%R]jbHZ#
$DDO9
8-;.Ejz!\A
} ,RPb<3 B
} 7P$*qj~Vh
//负责部分文件的抓取 ?NoNg^Of
**FileSplitterFetch.java Otq3nBZ
*/ IVxJN(N^
package NetFox; -M{szH
4e#g{,
G#7*O`
import java.io.*; $O|Xq7dp
import java.net.*; #un'?]tZF
&* VhtT?=5
>!fTWdD^
public class FileSplitterFetch extends Thread { B&MDn']fV/
W? G4>zA
J_)F/S!T
String sURL; //File URL !XTzsN
long nStartPos; //File Snippet Start Position K3zY-yIco
long nEndPos; //File Snippet End Position 3~sV-
int nThreadID; //Thread's ID [Q T ;~5
boolean bDownOver = false; //Downing is over \n}%RD-Ce
boolean bStop = false; //Stop identical \#[DZOI~
FileAccessI fileAccessI = null; //File Access interface [vr"FLM|9
]!ZZRe
! Vl)aL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l7t
{ (6fD5XtS
this.sURL = sURL; -c>3|bo
this.nStartPos = nStart; ndQw>
this.nEndPos = nEnd; PcsYy]Q/
nThreadID = id; Bl>m`/\1i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;1~n|IY
} nKE^km
"/R?XCBZsb
%qV:h#
public void run() s(X\7Hz_nC
{ `C4(C4u
while(nStartPos < nEndPos && !bStop) >:.c?{%g*
{ ^2dQVV.
x}ZXeqt{{
@0@WklAJA
try{ /R|?v{S1
URL url = new URL(sURL); Da<`| l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @Mya|zb
httpConnection.setRequestProperty("User-Agent","NetFox"); B}7j20:Z
String sProperty = "bytes="+nStartPos+"-"; Ifp8oL?S;
httpConnection.setRequestProperty("RANGE",sProperty); %0&,_jM/9
Utility.log(sProperty); 5]G%MB/|$
U2`:'
VK/L}^=GOO
InputStream input = httpConnection.getInputStream(); U9BhtmY
//logResponseHead(httpConnection); %]F/!n
6(7 56
J[}j8x?r
byte[] b = new byte[1024]; /\,3AInLb
int nRead; 7jw+o*;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uBG!R#T
{ mBL?2~M
nStartPos += fileAccessI.write(b,0,nRead); g8/ ,E-u
//if(nThreadID == 1) }>iNT.Lvd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8A0a/ 7Lj
} }#<Rs
SOPair <r
hcW>R
Utility.log("Thread " + nThreadID + " is over!"); y=Eb->a){
bDownOver = true; 3B]E2
//nPos = fileAccessI.write (b,0,nRead); #+<YFm\i
} x'-gvbj!
catch(Exception e){e.printStackTrace ();} ;~1xhpTk
} w.rcYywI
} B|o@|zF
J<0sT=/2$
QUkP&sz
//打印回应的头信息 r7R39#
public void logResponseHead(HttpURLConnection con) }x|q*E\
{ 9y[U\[H
for(int i=1;;i++) ;Mmu}
{ |J@ &lBlq
String header=con.getHeaderFieldKey(i); P\@kqf~pC
if(header!=null) uNEl]Q]<e]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mY=sh{ir
Utility.log(header+" : "+con.getHeaderField(header)); *|q{(KX
else B3yTN6-
break; GsO(\hR6^
} Z6b]EcP)#
} D\;5{,:d
g'!"klS93
N*[b26
public void splitterStop() N=U`BhL_
{ pq_U?_5Z'r
bStop = true; <^$ppwk$
} ES^JRX
u[SqZftmO
e)s l
} ld"rL6
Ne;0fkO
8_wh9
/* 1\{FKOt
**FileAccess.java AcJrJS)~
*//文件访问(定位，写) 3 [#Rm>,Vu
package NetFox; P(-
import java.io.*; /j3",N+I
B&7:=t,m(
!Mgo~h"]#
public class FileAccessI implements Serializable{ EXbZ9 o*
Txl|F\nK`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;Y8>?
RandomAccessFile oSavedFile; #I MaN%
long nPos; v2r|)c,h
wQ/.3V[
z&c}
public FileAccessI() throws IOException Af@\g-<W_
{ &E6V'*<93
this("",0); mcidA%
} "\vQVZd-E
;,uATd|
p,f$9t4
public FileAccessI(String sName,long nPos) throws IOException }%c>Hh
{ |Y6;8e`H
oSavedFile = new RandomAccessFile(sName,"rw"); MtF^}/0w!`
this.nPos = nPos; =[:E
oSavedFile.seek(nPos); E`xpZ>$mPx
} a*}>yad
4o";p}[b
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public synchronized int write(byte[] b,int nStart,int nLen) 2( I4h[
{ -da: j-_
int n = -1; K} T=j+
try{ KSS]%66Y
oSavedFile.write(b,nStart,nLen); R-<8j`[0
n = nLen; Wt@hST
} v:Gy>&
catch(IOException e) /kw;q{>?o
{ G=Lg5`3;,
e.printStackTrace (); .x] pJ9
} 6WIs*$T2*
=z"8#_3A
t_16icF9U
return n; PJ&L7
} $0OOH4
&PApO{#Q
ai?N!RX%H
} O#):*II`9
yJ]Va $M
x![.C,O
/* \ qq
**SiteInfoBean.java Zv@ Fr9m
*/ N5`z S79W
package NetFox; ?F!c"+C
&w`DF,k|
Q {~$7J
public class SiteInfoBean { $B<:SuV#
rH,@"(p\
;/pI@Ck
private String sSiteURL; //Site's URL VpB)5>
private String sFilePath; //Saved File's Path f8WI@]1F
private String sFileName; //Saved File's Name sSwY!";
private int nSplitter; //Count of Splited Downloading File X<$DNRN
mN.[bz
~:0w%
public SiteInfoBean() oP4+:r)LKD
{//nSplitter的缺省值为5 <]DUJuF-M
//default value of nSplitter is 5 j_h:_D4
this("","","",5); _Yp~Oj
} ^A=tk!C
hosY`"X
]jiVe_ OS<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Zo^]y'
{ mvTp,^1
sSiteURL= sURL; Jd v;+HN[
sFilePath = sPath; '3sySsD&O
sFileName = sName; $%'3w~h`
this.nSplitter = nSpiltter; vGPsjxk&
#639N9a~
dS <*DP
} d+5~^\lV
{,*vMQ<^
3iX\):4
public String getSSiteURL() `$6~QLUf
{ o[WDPIG
return sSiteURL; Z zp"CK 5
} eV(9I v[
0b n%L~KU
GP %hf{
public void setSSiteURL(String value) |#SZdXg
{ v@M^ukk'}
sSiteURL = value; /K1cP>oE
} h7T),UL
`F&~SU,
*TI?tD
public String getSFilePath() )u=W?5%=}
{ y5O &9Ckw
return sFilePath; 79d(UG'O
} XpE847!soL
Suo$wZ7J
}P{Wk7#Jq
public void setSFilePath(String value) <Q- m &
{ ;y1/b(t
sFilePath = value; yf8kBT:&S
} "8cI]~V
&|RTLGwX
{i8zM6eC
public String getSFileName() )$df6sq
{ 0%}*Zo(e+
return sFileName; J>nBTY,_<
} `JPkho
Vq{3:QBR
$6D*G-*8
public void setSFileName(String value) (*Q:'2e
{ %8xRT@Q
sFileName = value; |Nj6RB7
} C&*1H`n
Qe ip h
t:vBVDkD
public int getNSplitter() PR$;*|@
{ ^i!6z2/
return nSplitter; v0E6i!D/
} |K-`
|vGHhzZ|
Pgy[\t2K
public void setNSplitter(int nCount) 6W=V8
{ 7C3YVm6g
nSplitter = nCount; blIMrP%
} '/@wk#,
} k>.8lc\
P#XV_2
NY^0$h
/* i-5,*0e6m
**Utility.java ,R<9yEWm
*/ o,*D8[
package NetFox; j4!O,.!T
ty pbwfM]
p@4GI[4
public class Utility { 5~:/%+F0=
25{_x3t^
A( vdlj
public Utility() Pn[oo_)s
{ S**eI<QFSk
hdrsa}{g
(4A'$O2
} DmLx"%H3
6:Z8d%Z
//线程睡眠 0.n[_?<(
public static void sleep(int nSecond) NE8W--Cg|
{ @&WHX#
try{ ja';NIO-
Thread.sleep(nSecond); G7al@
} z^Ikb(KC
catch(Exception e) [{BY$"b#:
{ 5Q"w{ n
e.printStackTrace (); RLnL9)`W
} U{hu7
} TxP+?1t
=huV(THU
//日志 #m{*]mY@
public static void log(String sMsg) xV5UaD<
{ uy3<2L#.
System.err.println(sMsg); 6xJffl
} X4!7/&
/]xa}{^B
^Q$OzsEk
public static void log(int sMsg) TI< x;p
{ #[lhem]IC
System.err.println(sMsg); d)YlD]I
} Q]xkDr?
} jBw)8~tYm
J}X{8Ds9
FHSoj=
/* :Tg+)cZ
**TestMethod.java 67& hXIp
*/ &S*~EM.l8
package NetFox; K?!qNK
DdgiY9a.
!`Rh2g*o9
public class TestMethod { /;Tc]
([u|j
V;XKvH
public TestMethod() |0y#} |/
{ ///xx/weblogic60b2_win.exe U@mznf* J
try{ RQx8Du<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n_e'n|T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?W'p&(;
SiteFileFetch fileFetch = new SiteFileFetch(bean); '{,xQf*x
fileFetch.start(); XZM3zlg*
} `NsjtT'_
catch(Exception e){e.printStackTrace ();} sV
.9qK88fUR
lZ\8W^
} S13cQ?4
GrL{q;IO
^QRg9s,T<
public static void main(String[] args) |:=o\eu&
{ /8h=6"
new TestMethod(); H0Pxw P>q
} KeQcL4<
} YZBh}l6t
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