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)); )9r%% #
} 1Q5<6*QL"
for(int i=0;i<nEndPos.length-1;i++) dx}/#jMa
{ IJ8DN@w9
nEndPos = nStartPos[i+1]; X$9QW3.M
} ~@8d[Tb
nEndPos[nEndPos.length-1] = nFileLength; Yg[IEy
} F47n_JV!d
} pL@zZK0
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kPH^X}O$
//启动子线程 v8Zgog)V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bJm0
for(int i=0;i<nStartPos.length;i++) ~ ""MeaM8[
{ q4i8Sp>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j6vZ{Fx;w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $:[BB,$
nStartPos,nEndPos,i); $O'2oeM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s8[9YfuW
fileSplitterFetch.start(); 4C%>/*%8>
} ^-u HdafP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I_G>W3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iyYY)roB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h50StZ8Yr
nEndPos = " + nFileLength); *BsDHq-F~
// fileSplitterFetch[nPos.length-1].start(); EcoUpiL%2
^P/D8cXa4
b@/ON}gX
//等待子线程结束 cJEz>Z6[
//int count = 0; 49oW 'j
//是否结束while循环 2^6TrZA7M6
boolean breakWhile = false; (QSWb>np
?d<:V.1U@
GB?#1|,
while(!bStop) w3qf7{b
{ rA,Y_1b *
write_nPos(); d7J[.^\
Utility.sleep(500); q7&yb.<KD.
breakWhile = true; V6MT>T
93IOG{OAY
4AOS}@~W
for(int i=0;i<nStartPos.length;i++) U;{,lS2l
{ C;q}3c*L
if(!fileSplitterFetch.bDownOver) _(`X .D
{ mN{ajf)@
breakWhile = false; d._gH#&v
break; BG:`Fq"T
} +){a[@S@x
} 8TZA T%4
if(breakWhile) 9c{%m4
break; `A'I/Hf5
v^W?o}W
-`dxx)x
//count++; urXb!e{l
//if(count>4) fslk7RlSKg
// siteStop(); #IaBl?}r^
} $Kz\ h#}
NB5L{Gf6-
UD<^r]'x
System.err.println("文件下载结束！"); v?D kDnta
} W(a'^ #xe
catch(Exception e){e.printStackTrace ();} ZqbM%(=z(`
} 1mn$Rh&dO
C}=_8N
d=(Yl r
//获得文件长度 $^=jPk]+
public long getFileSize() '%-xe3
{ 8U<.16+5Q
int nFileLength = -1; mXU?+G0
try{ aI{@]hCo
URL url = new URL(siteInfoBean.getSSiteURL()); ~|Ih JzDt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wGzXp5 dl
httpConnection.setRequestProperty("User-Agent","NetFox"); e0N=2i?I#z
#4_O;]{'
nUud?F^_
int responseCode=httpConnection.getResponseCode(); jaO#><f
if(responseCode>=400) _c9 WWp?
{ \e:FmG
processErrorCode(responseCode); Wqs.oh
return -2; //-2 represent access is error 0|s$vqc
} udEb/7ZL
Fm$n@RbX
DAMpR3
String sHeader; hw ;dm
*T>#zR{
=!S@tuY
for(int i=1;;i++) ADyNNMcx
{ Tt<-<oyU.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _WDBG
//Utility.log(in.readLine()); 0J:U\S
sHeader=httpConnection.getHeaderFieldKey(i); m{lRFKx>s
if(sHeader!=null) h"BhTx7E}
{ )1Ma~8Y%r
if(sHeader.equals("Content-Length")) VJl &Bq+
{ /2_B$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Sa[EnC
break; =>:% n
} C`)^~C_]`3
} R5NRCI
else o >Rw}R
break; ;H y!0n
} E%k ]cZ
} 9Nag%o{*S>
catch(IOException e){e.printStackTrace ();} o^_W$4Fc
catch(Exception e){e.printStackTrace ();} Ql#W /x,e
1(:b{Bl
3d#9Wyxs
Utility.log(nFileLength); @dE 3
dS3>q<J*a
o}mhy`}
return nFileLength; e<L 9k}c
} w~Tq|kU[
ZM-/n>
VRd:2uDS
//保存下载信息（文件指针位置） Gh$y#0qr
private void write_nPos() [L*[j.r7[
{ %qNj{<&
try{ 5&n988gC8
output = new DataOutputStream(new FileOutputStream(tmpFile)); zfP[1
output.writeInt(nStartPos.length); 4uO @`0:x
for(int i=0;i<nStartPos.length;i++) 2[8fFo>
{ 4[5lX C
// output.writeLong(nPos); Sr ztTfY
output.writeLong(fileSplitterFetch.nStartPos); g/U$!d_
output.writeLong(fileSplitterFetch.nEndPos); 9{9#AI.G
} Jm]]>K8.3V
output.close(); [.#p
} f gK2.;>
catch(IOException e){e.printStackTrace ();} bG5^h
catch(Exception e){e.printStackTrace ();} T.R>xd`9 "
} taWirqd9
d739UhKC
rSF;Lp)}
//读取保存的下载信息（文件指针位置） m0%iw1OsH%
private void read_nPos() r{R[[]p
{ w!B,kqTG
try{ )T.pjl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M73VeV3DL
int nCount = input.readInt(); Y'<uZl^aX
nStartPos = new long[nCount]; B c,"12
nEndPos = new long[nCount]; fw1;i
for(int i=0;i<nStartPos.length;i++) +?"HTDBE||
{ #|{BGVp
nStartPos = input.readLong(); i_[ HcgT-
nEndPos = input.readLong(); Q8;x9o@p
} (1kn):
input.close(); 'uP'P#
} H7z>S G0
catch(IOException e){e.printStackTrace ();} AQnJxIL:
catch(Exception e){e.printStackTrace ();} z&C{8aQ'
} {dy` %It
a2cx
Z%Tq1O
private void processErrorCode(int nErrorCode) d{iu+=NXz
{ 7~!I2DV_
System.err.println("Error Code : " + nErrorCode); ==-7F3QP
} CU#L *kz
eHVdZ'%x
r!=]Q}`F
//停止文件下载 ;1{iF2jZ:
public void siteStop() dl*_ m3T
{ u|_LR5S!j
bStop = true; kz7vbY
for(int i=0;i<nStartPos.length;i++) RlI W&y
fileSplitterFetch.splitterStop(); e/]O<,*
c{'$=lR "
D_l/Gxdpr
} LCo1{wi
} Ht`<XbQ>
//负责部分文件的抓取 7.7Cluh5,
**FileSplitterFetch.java '|YtNhWZ?
*/ K:>NGGY8r
package NetFox; ILkjz^
} D/+<
')AByD}Hi]
import java.io.*; ALE808;|
import java.net.*; D:YN_J"kV
l1-4n*fU
&K9VEMCEX
public class FileSplitterFetch extends Thread { ".~MmF
5z9r S<
!XgQJ7y_Z
String sURL; //File URL FSW3'
long nStartPos; //File Snippet Start Position o-\ok|,)#j
long nEndPos; //File Snippet End Position "?oo\op
int nThreadID; //Thread's ID 8eOl@}bV
boolean bDownOver = false; //Downing is over 'sm[CNzS
boolean bStop = false; //Stop identical ~u_K&X
FileAccessI fileAccessI = null; //File Access interface t Y:G54d=_
hrJ$%U
g>6:CG"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HO266M
{ [b7it2`dl
this.sURL = sURL; B]'e$uyL7
this.nStartPos = nStart; Tjd&^m
this.nEndPos = nEnd; KcIc'G 9
nThreadID = id; T5K-gz7A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K%Usjezv&
} )HJK '@
+ 6x"trC
GAg.p?Sq
public void run() >[Xm|A#
{ 2.StG(Y!
while(nStartPos < nEndPos && !bStop) WafdE
{ Q;XXgX#l
3mpP|b"
{M`
try{ L\QQjI{
URL url = new URL(sURL); 3M}AxEu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z7`5x
httpConnection.setRequestProperty("User-Agent","NetFox"); 8pXfT%]
String sProperty = "bytes="+nStartPos+"-"; mBw2
httpConnection.setRequestProperty("RANGE",sProperty); umJay/>
Utility.log(sProperty); \1=T sU&^
rER~P\-
f2uZK!:m
InputStream input = httpConnection.getInputStream(); k TFz_*6.
//logResponseHead(httpConnection); B"~U<6s0
PLO\L W
"F&Tnhh4
byte[] b = new byte[1024]; b cC\
int nRead; l9]o\JFXk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *Zc9yZl2
{ Rb{+Ki
nStartPos += fileAccessI.write(b,0,nRead); /DLr(
//if(nThreadID == 1) 4qqF v?O[r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x2sN\tOh^
} V^j3y`K
2;&mkcK'
?+3R^%`V
Utility.log("Thread " + nThreadID + " is over!"); \U==f&G?J
bDownOver = true; =ft9T&ciD
//nPos = fileAccessI.write (b,0,nRead); \V._Z>]
} 91BY]N
catch(Exception e){e.printStackTrace ();} #uQrJh1o8
} l>A\V)
} 5kK=S
j1'\R+4U
CoKiQUW
//打印回应的头信息 gBMta+<fE~
public void logResponseHead(HttpURLConnection con) !.9l4@z#
{ kJ/+IGV^v
for(int i=1;;i++) A$/KP\0Y2
{ ]a8eDy
String header=con.getHeaderFieldKey(i); g* %bzfk=|
if(header!=null) Y3D3.T6Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1oB$MQoc
Utility.log(header+" : "+con.getHeaderField(header)); |p;4dL
else fwRGT|":B
break; 0rV/qMo;K
} 2q+la|1Cr
} DKR<W.!*t
OdO{xG G@
{PL,VY)Z
public void splitterStop() BeAk21xb
{ SO7(K5H,
bStop = true; rZ pbu>S
} C=8H)Ef,l
cvxIp#FbW
,&0Z]*
} `$H7KIG
^n t~-%
JFe4/ V
/* <|otZJ'2r
**FileAccess.java ! &y
*//文件访问(定位，写) JAN|aCzD
package NetFox; ,Ie<'>hd
import java.io.*; tzZ|S<e6=\
6!@0VI&P
l+oDq'[q"
public class FileAccessI implements Serializable{ ;D:=XA%
)#C_mB$-#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S45'j(S=
RandomAccessFile oSavedFile; OthG7+eF
long nPos; 61G|?Aax
{d8^@UL
S=4R5igrC
public FileAccessI() throws IOException V_jiOT!
{ vXc!Zg~
this("",0); /=bSt
} cY{I:MA+h@
*jGPGnSo
(yfXMp,x
public FileAccessI(String sName,long nPos) throws IOException ]XY0c6 <
{ fa"\=V2S
oSavedFile = new RandomAccessFile(sName,"rw"); ZH% we
this.nPos = nPos; Ohc^d"[7
oSavedFile.seek(nPos); hRk,vB]
} W.IH#`-9E
cFw3Iw"JJ
B+|IZoR
public synchronized int write(byte[] b,int nStart,int nLen) 2f `&WUe
{ -W9gH
int n = -1; 9g96 d-
try{ ci;&CHa
oSavedFile.write(b,nStart,nLen); -7&?@M,u
n = nLen; Ny]lvgu9X
} r-*l1([eW
catch(IOException e) %Sc=_%6
{ 1PmX."a
e.printStackTrace (); k2pT1QZnt
} :fhB*SYK
*aI~W^N3
3XnE y +
return n; wBLsz/
} ZH!;z-R
}H5/3be
ZxI]I1)
} &eU3(F`.
f P+QxOz
`6UtxJSx
/* hw*1gm
**SiteInfoBean.java C[R`Ml
*/ +eC3?B8rN
package NetFox; uC)Zs, _5
zqY)dk
]uAS+shQ&
public class SiteInfoBean { '\ XsTs#L
gXF.on4B
/ xs9.w8-
private String sSiteURL; //Site's URL 7pz\ScSe
private String sFilePath; //Saved File's Path @\!ww/QT
private String sFileName; //Saved File's Name (xbIUz.
private int nSplitter; //Count of Splited Downloading File db'K!M)
2?*||c==*
vsc&Ju%k
public SiteInfoBean() }{A?PHV5
{//nSplitter的缺省值为5 j"i#R1T
//default value of nSplitter is 5 \x(.d.l/
this("","","",5); UP?D@ogl<
} j6HR&vIM
xuF5/(__
g[AA,@p+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j!7Qw 8
{ 1!d)PK>1$
sSiteURL= sURL; VJ*\pM@no
sFilePath = sPath; 86y%=!bS
sFileName = sName; I'?6~Sn3
this.nSplitter = nSpiltter; =E!x~S;N
a&N%|b K
an.`dBm
} oCbpK
B2Qp}
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public String getSSiteURL() 9N^+IZ@l
{ :SK<2<8h
return sSiteURL; BD4`eiu"
} #%4=)M>^
Hk~k@Wft
+ LS3T^
public void setSSiteURL(String value) _=?2 3
{ z|Ap\[GS
sSiteURL = value; EQ/^&
} %6Rn4J^^
`/0u{[
W-ez[raY
public String getSFilePath() `On3/gU|
{ P,U$ %C!
return sFilePath; d-h"JZ9
} UP]1(S?
"1K:/n
#cO+<1
public void setSFilePath(String value) `Klrr
{ ODek%0=
sFilePath = value; mbGcDG[HQ
} >K5~:mx#3
5a6VMqQ6
*<xrp*O
public String getSFileName() 2uEhOi0I
{ xG8`'SNY
return sFileName; K?[)E3
} Tt%}4{"
05"qi6tncz
$ o" L;j
public void setSFileName(String value) SHwRX? B|
{ yjFe'
sFileName = value; WcU@~05b
} Ok*Z
>T QZk4$
{\L|s5=yr
public int getNSplitter() @C=M UT-!
{ #52NsVaT@
return nSplitter; eG4>d^`c
} rFfy#e
D'nL
?&xlT+JM
public void setNSplitter(int nCount) K#wK1 Sv
{ kN.B/itvA
nSplitter = nCount; !LiQ 1`V{
} -;U3w.-
} EX+,:l\^
n]v7V&mj\
<6R"h-u"
/* R1/q3x
**Utility.java GG+5/hU
*/ m!:.>y
package NetFox; MJ\r 4n
+sRP<as
c.0]1
public class Utility { F"[3c6yF
ABZ06S/
hiN/S|JN8y
public Utility() ,VWGq@o%
{ #%8 w
g|4w8ry
nP;;MX:B
} !k-` eJ|
H-2_j
//线程睡眠 9n 6fXOC
public static void sleep(int nSecond) 3q?5OL^$
{ `kPc!I7Y
try{ ;`X~ k|7K
Thread.sleep(nSecond); YZ**;"<G
} u7#z^r
catch(Exception e) 6__K#r
{ 3S;N(A4
e.printStackTrace (); cix36MR_
} f?maa5S
} ^j=bObaX
${>DhfF
//日志 Sr"/-
public static void log(String sMsg) s:b"\7
{ c3#q0Ma
System.err.println(sMsg); Vo >Xp
} ="3,}qR
K}K)`bifw
UJn/s;$.e
public static void log(int sMsg) 02pplDFsM
{ hfv%,,e
System.err.println(sMsg); /WYh[XKe
} dhtb?n{
} OpQ8\[X+
KuXkI;63J>
,E9d\+j
/* anC+r(jjg9
**TestMethod.java eO[c lB
*/ o|rzN\WJn
package NetFox; pX_b6%yX(
F~R7~ZE
7kd|K b(
public class TestMethod { OD|1c6+X
,ux+Qz5(
]7vf#1i<
public TestMethod() y<*-tZV[
{ ///xx/weblogic60b2_win.exe %Rarr
try{ l"5y?jT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )5GQJiY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1.0J2nZpt
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2*Q3.2 Z
fileFetch.start(); *<q4S(l
} ]| WA#8_|
catch(Exception e){e.printStackTrace ();} FUqt)YHi
]nc2/S%
KTv4< c]
} s#P:6]Ar
sUciFAb
'hIU_
public static void main(String[] args) tT-=hDw
{ L[]BzsIv
new TestMethod(); -_|]N/v\
} zo44^=~%
} x8/us
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