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)); )ZrS{vY
} )o-Q!<*1
for(int i=0;i<nEndPos.length-1;i++) t#%R q
{ '>$]{vQ3
nEndPos = nStartPos[i+1]; MX4]Vpv
} b@3_L4~
nEndPos[nEndPos.length-1] = nFileLength; .q&'&~!_
} b=~i)`
} h~{aGo
OpM(j&
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//启动子线程 ,rJXy_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A)%A!
for(int i=0;i<nStartPos.length;i++) [,2|Flf e
{ {hln?'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ig3;E+*>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :qChMU|Y6
nStartPos,nEndPos,i); d*)CT?d&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nhIa175'
fileSplitterFetch.start(); 7jnIv];i
} %dQxJMwj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +f*OliMD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^c:Fy+fb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z2im@c67{
nEndPos = " + nFileLength); "D?z
// fileSplitterFetch[nPos.length-1].start(); z]b>VpW:
`tjH<
*tm0R>?!
//等待子线程结束 JXyM\}9-X
//int count = 0; Ag F,aZU
//是否结束while循环 JQ4{` =,b
boolean breakWhile = false; gTA%uRBa
dnV[ P
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while(!bStop) Or !+._3i
{ hXqD<?
write_nPos(); V& C/Z}\
Utility.sleep(500); v3v[[96p
breakWhile = true; uV 7BK+[O
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@+atBmt
for(int i=0;i<nStartPos.length;i++) J|&JD?
{ rvr-XGK36\
if(!fileSplitterFetch.bDownOver) pABs!A`N
{ !Hys3AP
breakWhile = false; x\Z'2?u}
break; n_3O-X(
} 2tal
} ^pJ!isuqu
if(breakWhile) kOh{l: 2-+
break; 5|jw^s7
#v<QbA
MwmUgN"g
//count++; &QhX1dT+
//if(count>4) wn)JXR
// siteStop(); ~I{n^Q/a
} +-E~6^>
$H+VA@_
e["2QIOe
System.err.println("文件下载结束！"); LBF 1;zjK
} =m5SK5vLKT
catch(Exception e){e.printStackTrace ();} gn3jy^5
} Nbp!teH6
SRDXfkoI
X^WrccNX
//获得文件长度 JPGzrEaZ
public long getFileSize() |j 6OM{@
{ B" 3dQwQ
int nFileLength = -1; tU_y6
try{ irN6g#B?
URL url = new URL(siteInfoBean.getSSiteURL()); <!pY$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3E3HL7
httpConnection.setRequestProperty("User-Agent","NetFox"); ,\qs4&
;]_o4e6\p
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int responseCode=httpConnection.getResponseCode(); 6ND`l5
if(responseCode>=400) 2 !'A:;
{ n> ^[T[.S
processErrorCode(responseCode); Q'%PNrN
return -2; //-2 represent access is error W3iZ|[E;
} EY \H=@A
Y[L-7^o@y
q7"7U=W0
String sHeader; A<W6=5h
?2>FdtH
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for(int i=1;;i++) \?jeWyo
{ NMA}Q$o s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jAud {m*T
//Utility.log(in.readLine()); /PLn+-
sHeader=httpConnection.getHeaderFieldKey(i); 1AU#%wIEP
if(sHeader!=null) cq$i
{ QcgfBsv96
if(sHeader.equals("Content-Length")) &LbJT$}V
{ !ET~KL!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [ :zO}r:
break; K# Jk _"W
} F{UP;"8'
} J9=m]R8T
else 3;a<_cE*@
break; }Q";aU0^
} zL\OB?)5J
} *6} N =Z
catch(IOException e){e.printStackTrace ();} hcyM6:}
catch(Exception e){e.printStackTrace ();} Ntbg`LGf'!
-=(!g&0
Dq)j:f#QM
Utility.log(nFileLength); z`\F@pX%wC
e6!LSx}y
tzs</2 G,
return nFileLength; yV"ZRrjO'Z
} f4BnX(1u
"I QlVi
f"St&q>[s
//保存下载信息（文件指针位置） O)"gS!,
private void write_nPos() 9D4NX<_
{ 95z]9UL
try{ ca>Z7qT!
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0X^Ke(/89
output.writeInt(nStartPos.length); ;g~TWy^o
for(int i=0;i<nStartPos.length;i++) /r=tI)'$
{ H=\3Jj(4
// output.writeLong(nPos); pZeE61c/
output.writeLong(fileSplitterFetch.nStartPos); k68F-e[i^
output.writeLong(fileSplitterFetch.nEndPos); .B\5OI,]
} "U\4:k`:
output.close(); A*um{E+
} _vZ"4L+Iw+
catch(IOException e){e.printStackTrace ();} !&"<oPjr+
catch(Exception e){e.printStackTrace ();} t 89!Ihk
} C?2'+K
$_x^lr
mVR P~:+
//读取保存的下载信息（文件指针位置） bP^Je&nS*
private void read_nPos() NM06QzE
{ ZfB" E
try{ Yboiwy,n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PP!SK2u"L
int nCount = input.readInt(); A$w4PVS
nStartPos = new long[nCount]; !U5Wr+83
nEndPos = new long[nCount]; n+PzA[
for(int i=0;i<nStartPos.length;i++) )LyojwY_g
{ 'Tc]KXD6
nStartPos = input.readLong(); a|?4)
nEndPos = input.readLong(); >hr{JJe
} EbdfV-E
input.close(); lgb?)=
} 3%E74 mOcD
catch(IOException e){e.printStackTrace ();} (x3.poSt
catch(Exception e){e.printStackTrace ();} pbU!dOU~e
} c.j$9=XLBG
,JEFGI{
|Z*J/v'@p
private void processErrorCode(int nErrorCode) }5(Ho$S(
{ HTyLJe
System.err.println("Error Code : " + nErrorCode); B~_d^`
} ~SnSEhE
7bV{Q355P
/;utcc
//停止文件下载 a(0*um(
public void siteStop() smry2*g
{ TEaJG9RU>v
bStop = true; uNHF'?X
for(int i=0;i<nStartPos.length;i++) 1+U
fileSplitterFetch.splitterStop(); YWxc-fPZ
UNkCL4N
l'TWkQ-
} Iwc{R8BV
} GPGm]Gt
//负责部分文件的抓取 4A2?Uhpy
**FileSplitterFetch.java >b]S3[Q(
*/ t>[KVVg W
package NetFox; (4Zts0O\
/\WQxe
<0PT"ij
import java.io.*; ,.qMEMm
import java.net.*; r9ww.PpNk#
f?'JAC*
wV^V]c?U
public class FileSplitterFetch extends Thread { I:d[Q s
:=[XW?L%x
n8DxB@DI
String sURL; //File URL KFFSv{m[
long nStartPos; //File Snippet Start Position ?IGVErnJJC
long nEndPos; //File Snippet End Position [NTtz <i@
int nThreadID; //Thread's ID :P(K2q3
boolean bDownOver = false; //Downing is over &Ky_v^
boolean bStop = false; //Stop identical :"!9_p(,,
FileAccessI fileAccessI = null; //File Access interface 14"J d\M8
](^(=%
Ix(><#P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6O}`i>/6M
{ J|w)&bV
this.sURL = sURL; m:/wG& !
this.nStartPos = nStart; MC{ 2X
this.nEndPos = nEnd; 44F`$.v96
nThreadID = id; Rh>}rGvCUN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ey4z.s'-l
} V@\%)J'g
@`,1:
-%I2[)F<
public void run() B0ndcB-
{ Y]3>7q%
while(nStartPos < nEndPos && !bStop) al[n,u
{ X 51Yfr
iT)z_
T0]*{k(FR
try{ ]7/ b/J
URL url = new URL(sURL); @-&s: Qli
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7ek&[SJ>,/
httpConnection.setRequestProperty("User-Agent","NetFox"); MG{YrX)oi
String sProperty = "bytes="+nStartPos+"-"; HX6Ma{vBk
httpConnection.setRequestProperty("RANGE",sProperty); &|`C)6[C
Utility.log(sProperty); kGN+rHo
"&%#!2
E]6z8juO6
InputStream input = httpConnection.getInputStream(); 'gt-s547
//logResponseHead(httpConnection); I'@Ydt2
Q(\4]i< S
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byte[] b = new byte[1024]; kWrp1`
int nRead; e~"fn*"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $]q8, N|1
{ Bk+{RN(w
nStartPos += fileAccessI.write(b,0,nRead); <$hu
//if(nThreadID == 1) (k|_J42[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ? mhs$g>
} p}<w#p |
~jb"5CX
]J#9\4Sq
Utility.log("Thread " + nThreadID + " is over!"); nQ/E5y
bDownOver = true; 25&J7\P*
//nPos = fileAccessI.write (b,0,nRead); |eWjYGwJa
} mSo_} je(
catch(Exception e){e.printStackTrace ();} ;IpT} ,
} pm6>_Kz
} (X?/"lC)
;-Jb1"5
ScSZGs 5&
//打印回应的头信息 ru7RcYRq
public void logResponseHead(HttpURLConnection con) Dxk+P!!K
{ B)QHM+[=F
for(int i=1;;i++) p3}?fej&|
{ -> J_ ~
String header=con.getHeaderFieldKey(i); &EpAg@9!
if(header!=null) CQpCS_M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,do58i K
Utility.log(header+" : "+con.getHeaderField(header)); HyR!O>
else U5r7j
break; LbII?N8`N
} Tt>8?
} +z$pg
O%ug@& S{
W\L`5CW
public void splitterStop() "ax..Mh\y
{ <u=4*:QE
bStop = true; |> _!eS\=<
} >pr=|$zk=
yu;SH[{Wi
e*.b3z
} VnT>K9&3
SnYLdwgl
H&yD*@
/* XB[<;*Iz
**FileAccess.java 0j_bh,zG#
*//文件访问(定位，写) ZlojbL@|4
package NetFox; EutP\K_Y
import java.io.*; \t|M-%&)4
NzW`B^p
Ve/xnn]'
public class FileAccessI implements Serializable{ ?r2#.W
$8crN$ye
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0=="^t_
RandomAccessFile oSavedFile; =GXu 5 8
long nPos; aIXdV2QS
)$Z=t-q
wWXD\{Hk
public FileAccessI() throws IOException 2+Wzf)tB
{ ^Eo=W/
this("",0); ;zdxs'hJ
} >dM8aJzC
zY|klX})
NOS>8sy
public FileAccessI(String sName,long nPos) throws IOException EbZdas!l
{ ]0r|_)s
oSavedFile = new RandomAccessFile(sName,"rw"); cGwf!hA
this.nPos = nPos; p)~lL
oSavedFile.seek(nPos); Tb1U^E:
} wap3Kd>MP
_e7-zg$/
[qoXMuC|P
public synchronized int write(byte[] b,int nStart,int nLen) z7-k`(l4
{ @WKzX41'
int n = -1; 99EXo+g
try{ [0UGuj
oSavedFile.write(b,nStart,nLen); eVl'\aUd
n = nLen; J/6`oh?,Q
} wIf {6z{
catch(IOException e) ,]5Ic.};p
{ _xLHrT!y
e.printStackTrace (); X1vNF|o~
} HBB{m
DSxUdEK6
=\{\g7
return n; Y\=FLO9
} 6yy;JQAke
}17.~
&Z^l=YH,
} tV/Z)fpyH
IooNb:(
n& $^04+i
/* !JBae2Z
**SiteInfoBean.java {5|("0[F
*/ |([R'Orm
package NetFox; /1`cRyS
}!TL2er_
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public class SiteInfoBean { [= "r<W0
%/.a]j!
,pBh`av
private String sSiteURL; //Site's URL T$=4O9G
private String sFilePath; //Saved File's Path [\Qr. 2
private String sFileName; //Saved File's Name cubUq5
private int nSplitter; //Count of Splited Downloading File \x>65;
O3o: qly!
>ulY7~wUv
public SiteInfoBean() \b*X:3g*
{//nSplitter的缺省值为5 ^S#t|rN
//default value of nSplitter is 5 G9g6.8*&
this("","","",5); },[;O^Do^{
} Yct5V,X^
0qFH s
MEiRj]t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |3? 8)z\n
{ ,DnYtIERo
sSiteURL= sURL; mceG!@t
sFilePath = sPath; 1t9.fEmT
sFileName = sName; l|V;Ys5f
this.nSplitter = nSpiltter; FP"$tt(
c6Q(Ygc
Ejq#~Zhr!
} kVS?RHR
Ov82ibp_1
#2xSyOrmf
public String getSSiteURL() Rb}KZ+o"Z
{ ~]L}p
return sSiteURL; j*;N\;iL!*
} H g5++.Bp
e1q"AOV6
A 699FQ
public void setSSiteURL(String value) `3q;~ 9
{ DW(~Qdk
sSiteURL = value; 0F;,O3Q
} 1f(DU4h
k6\^p;!Y
G"y.Z2$
public String getSFilePath() PKq-@F%X
{ 8X&Ya =
return sFilePath; "?.~/@
} <1~^C
%"A_!<n@*`
[{&jr]w`|
public void setSFilePath(String value) q\9d6u=Gm
{ I]}>|
sFilePath = value; 8Og3yFx[rt
} }PeZO!K
,,=apyr#&
sP$Ks#/
public String getSFileName() tu%[p 4
{ >adV(V<
return sFileName; Ov9Q?8KzM
} _ :^7a3I
w36(p{#vp
w>~M}Ahj
public void setSFileName(String value) 8)0L2KL'
{ EA{U!b]cU
sFileName = value; v+1i=s2$
} %3Bpn=k>
D>wZ0p b-
R21~Q:b!
public int getNSplitter() u@.>WHQN
{ VS/;aG$&y
return nSplitter; PK rek
} $R^lo$(
(xyS7q]m
8TZENRzx-|
public void setNSplitter(int nCount) Lu>H`B7Q"
{ nwM)K
nSplitter = nCount; h ; kfh.
} )%JD8;[Jq
} <`g3(?
E(L<L1:"
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/* ;rBp1[qVe
**Utility.java +2T!z=
*/ WtX>Qu|
package NetFox; oO=o|w|T
7!2 HNg
BgRZ<B`
public class Utility { b1!@v+
uMFV%+I
E8/rZ~0O~
public Utility() ehOs9b
{ ^b53}f8H
xFsmf<Vm
.RRlUWu
} [!?wyv3
T{S4|G1R6
//线程睡眠 QB 77:E
public static void sleep(int nSecond) t=dO
{ 8sw,k
try{ HcJE0-"
Thread.sleep(nSecond); l C\E
} wq72%e
catch(Exception e) e.X@] PQJQ
{ 9qH[o?]
e.printStackTrace (); 3ps,uozj
} C{Blqf3V0
} D@vMAW
\f"?Tv-C'
//日志 N8+P
public static void log(String sMsg) ,k*F`.[
{ 4MX7=!E
System.err.println(sMsg); x N`T
} $A?}a
u@D.i4U
k!E"wJkpz
public static void log(int sMsg) F";FG 0
{ 1VfSSO
System.err.println(sMsg); .fJ*c
} g@E&uyM
} K}2Npo FS
dt~iw
]P*!'iYN(
/* 97x%w]kV
**TestMethod.java @}eNV~ROu
*/ %CT!$Y'n
package NetFox; &|=?acv
4 =Fg!Eu<
37KU~9-A
public class TestMethod { T}2:.Hk:N
; J2-rh
_$(GRNRYK
public TestMethod() k5X b}@
{ ///xx/weblogic60b2_win.exe SOI)/u
try{ &"AQ;%&N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L<)Z>@fR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0P9Wy!f7
SiteFileFetch fileFetch = new SiteFileFetch(bean); "/y|VTV"
fileFetch.start(); *8206[y
} KW>VOW<.
catch(Exception e){e.printStackTrace ();} "%kGRHq
c *1S}us
RHXvee55
} Dqr9Vv
6UI>GQ
;z0"Ox=7
public static void main(String[] args) oeGS
{ Bbs5f@E
new TestMethod(); f+^c@0que
} xOM_R2Md
} 08io<c,L
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