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)); m2>$)\-;
} Mq Q'Kjo
for(int i=0;i<nEndPos.length-1;i++) D&|HS!
{ G@8wv J
nEndPos = nStartPos[i+1]; J}Ji /
} C)(/NGf
nEndPos[nEndPos.length-1] = nFileLength; v&3 Oc
} V[^+lR
} Y5R|)x
K[R.B!;N
[n2)6B\/
//启动子线程 30<3DA_P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :)j& t>aP
for(int i=0;i<nStartPos.length;i++) ;uyQR8
{ Jie=/:&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3!Cab/T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (P|k$S?m
nStartPos,nEndPos,i); 6e4A|<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5$%CRm
fileSplitterFetch.start(); q?=_{oH9
} 7i0;Ss*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (Nn)_caVb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5z@QAQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IiZXIG4H
nEndPos = " + nFileLength); M2piJ'T4u
// fileSplitterFetch[nPos.length-1].start(); 1(vcM
]~kgsI[E
!HSX:qAP$
//等待子线程结束 i/aj;t
//int count = 0; )Kg_E6
//是否结束while循环 ,'a[1RN
boolean breakWhile = false; Z/+H
;s!GpO7+
^^kL.C Ym
while(!bStop) n{E9p3i
{ }ZkGH}K_}
write_nPos(); Ie'iAY
Utility.sleep(500); ~NZ}@J{00_
breakWhile = true; _GsHT\
dEK bB
R/ 3#(5
for(int i=0;i<nStartPos.length;i++) 1pZ[rM'}
{ ~'t+X
if(!fileSplitterFetch.bDownOver) T~)zgu%q_
{ Azag*M?
breakWhile = false; .(X!*J]G
break; wOrpp3I
} E#/vgm=W;
} )mE67{YJh~
if(breakWhile) 0uhIJc'2
break; VCc57Bo
g7O, <
v.{I^=
//count++; h45RwQ5Z
//if(count>4) 8rM1kOCf
// siteStop(); LT6VZ,S
} Xf*}V+&WN
3y]rhB
{^6<Ohe4j
System.err.println("文件下载结束！"); 0w ;#4X:m
} u!9bhL`
catch(Exception e){e.printStackTrace ();} [J+]1hCZ|
} qY|NA)E)Bp
6d%)MEM
oPC qv
//获得文件长度 @+(a{%~7y
public long getFileSize() 6M X4h
{ *Fz#x{zt
int nFileLength = -1; N3o kN8d
try{ :B1a2Y^"
URL url = new URL(siteInfoBean.getSSiteURL()); /*hS0xN*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -r@/8"
httpConnection.setRequestProperty("User-Agent","NetFox"); _T(MMc
.R{+Pz D
THHA~;00YN
int responseCode=httpConnection.getResponseCode(); TTm
if(responseCode>=400) K])| V
{ vH/Y]Am
processErrorCode(responseCode); .8/W_iC92
return -2; //-2 represent access is error :IX_}|
} brClYpp,h
nQM7@"R
,7*-%05[\
String sHeader; +<W8kb
9}Qrb@DT
@ )m9#F
for(int i=1;;i++) ff<adl-
{ eVB.g@%T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +d/^0^(D\5
//Utility.log(in.readLine()); 4&'_~qU
sHeader=httpConnection.getHeaderFieldKey(i); <]kifiN#
if(sHeader!=null) Z=CY6Zu7
{ 2mVLR;s{_
if(sHeader.equals("Content-Length")) ts~$'^K[-
{ ~n`G>Oe3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9Qhk~^ngg
break; aIABx!83>
} AlQ
} 4Q FX
else 8I|2yvhP
break; =OU]<%
} NJTC+`Hm
} PbN"+qM
catch(IOException e){e.printStackTrace ();} 8GFA}_(^R
catch(Exception e){e.printStackTrace ();} mB]Y;R<
]6 vqgu
'c|Y*2@
Utility.log(nFileLength); O.~@V(7ah
um$K^
6 &)fZt
return nFileLength; b1`(f"&l
} sT"h)I)]*
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_Q3Ad>,U
//保存下载信息（文件指针位置） MX#MDA-4
private void write_nPos() \qh -fW; #
{ %Jc>joU
try{ VIjsz42C
output = new DataOutputStream(new FileOutputStream(tmpFile)); J((.zLvz
output.writeInt(nStartPos.length); MOEB{~v`;
for(int i=0;i<nStartPos.length;i++) UCP4w@C
{ pr(16P
// output.writeLong(nPos); Ug|o($CY
output.writeLong(fileSplitterFetch.nStartPos); @43o4,
output.writeLong(fileSplitterFetch.nEndPos); d^<a)>5h
} =w&<LJPJ
output.close(); h7H#sL[^
} >@o}l:*
catch(IOException e){e.printStackTrace ();} k$7@@?<
catch(Exception e){e.printStackTrace ();} 6hs2B5)+
} #e:*]A'I
_,2P4
n|oAfJUk,
//读取保存的下载信息（文件指针位置） @#%rTKD9F
private void read_nPos() kGZ_/"iuO
{ ' 1aU0<
try{ =Xc[EUi<;g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~4~-^ t
int nCount = input.readInt(); Bjz\L0d
nStartPos = new long[nCount]; D~xUr)E
nEndPos = new long[nCount]; {&Fh$H!
for(int i=0;i<nStartPos.length;i++) $MmCh&V
{ t;@VsQ8
nStartPos = input.readLong(); @:~O
nEndPos = input.readLong(); M_2[Wypw
} m$xyUv1
input.close(); 2dr[0tE
} ul e]eRAG
catch(IOException e){e.printStackTrace ();} Hize m!
catch(Exception e){e.printStackTrace ();} !j)H!|R
} o4b!U%
[Pdm1]":(
)CzWq}:
private void processErrorCode(int nErrorCode) KsGSs9
{ |*N.SS
System.err.println("Error Code : " + nErrorCode); 8E/]k\
} byv(:xk|'e
ZpHT2-baVe
FG~p_[K
//停止文件下载 Z3G>DF:$
public void siteStop() QY2!.a^q
{ @\_tS H
bStop = true; \>j._#t$h
for(int i=0;i<nStartPos.length;i++) ~u&3Ki*x
fileSplitterFetch.splitterStop(); ctOC.
<GShm~XD2
-uiZp !
} ML0o:8Bd\
} ]do0{I%\eq
//负责部分文件的抓取 r+;C}[E
**FileSplitterFetch.java M"K$81
*/ 0gVylQ
package NetFox; :x97^.eW~
`-4c}T
0z."6r
import java.io.*; O@3EJkv
import java.net.*; g!7/iKj:
(^eSm]<
PDX^MYoN
public class FileSplitterFetch extends Thread { !a3cEzs3
N40.GL0s
K3?7Hndf2
String sURL; //File URL +J$[RxQ#
long nStartPos; //File Snippet Start Position c\.4I4uy
long nEndPos; //File Snippet End Position <!&nyuSz
int nThreadID; //Thread's ID G3 #c
boolean bDownOver = false; //Downing is over PP&AF?C
boolean bStop = false; //Stop identical /wI$}X5o~
FileAccessI fileAccessI = null; //File Access interface 5_M9T3
uKh),@JV
j0o_``
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .0#?u1gXsX
{ 9wC q
this.sURL = sURL; hti)<#f
this.nStartPos = nStart; iO3@2J
this.nEndPos = nEnd; sxl29y^*
nThreadID = id; F)lDK.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d/- f]
} pF#nj`L
,;H)CUe1"
WU{G_Fqaz
public void run() ar=uDb;
{ xc8MOm
while(nStartPos < nEndPos && !bStop) I8`@Srw8
{ e0+N1kY
2>.B*P
.'p_j(uv
try{ JpxJZJ
URL url = new URL(sURL); LnxJFc:1K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sk$MJSE ~
httpConnection.setRequestProperty("User-Agent","NetFox"); br>"96A1l
String sProperty = "bytes="+nStartPos+"-"; _*9eAeJ
httpConnection.setRequestProperty("RANGE",sProperty); &I:5<zK{
Utility.log(sProperty); {*`qL0u]^
C*b!E:
#)hM]=,e
InputStream input = httpConnection.getInputStream(); eL#pS=
//logResponseHead(httpConnection); ;a XcGa
%rzC+=*;
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byte[] b = new byte[1024]; *rK}Ai
int nRead; :o&qJ%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N{tNe-5
{ 4EJ
nStartPos += fileAccessI.write(b,0,nRead); siZw-.
//if(nThreadID == 1) F# y5T3(P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lSUEE0V%Q
} 4W*52*'F,
vkOCyi?c
OSK3X Qc
Utility.log("Thread " + nThreadID + " is over!"); H.hF`n
bDownOver = true; ,Za!
//nPos = fileAccessI.write (b,0,nRead); |#LU"D
} D4ESo)15'
catch(Exception e){e.printStackTrace ();} /=*h\8c~
} xJa
} 1CU-^j
Jv %,v?
UIi;&[
//打印回应的头信息 B?`Gs^Y{z
public void logResponseHead(HttpURLConnection con) xqs{d&W
{ HJo&snT3
for(int i=1;;i++) WolkW:(Cg
{ NGOc:>}k>
String header=con.getHeaderFieldKey(i); <La$'lG4J
if(header!=null) J70#pF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {~_X-g5|]
Utility.log(header+" : "+con.getHeaderField(header)); zt/b S/
else WUm83"
break; yl/-!
} @e8b'w3
} (/UW}$] h
c>#T\AEkF
!K-lO{Z^
public void splitterStop() 7g8}]\i+
{ 2a|9D\
bStop = true; h+<vWo}H
} ?{[ISk)
IL;JdIa
l2vIKc
} +:k Iq
D[32t0
?f f!(U
/* KX D&FDkF
**FileAccess.java W/DSj :
*//文件访问(定位，写) "HX,RJ @^K
package NetFox; ]CHO5'%,$
import java.io.*; ^YG'p?r.s
tj$&89
@{N2I$%6
public class FileAccessI implements Serializable{ d5Hp&tm
_/(DEF+G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1W3+ng
RandomAccessFile oSavedFile; 4efIw<1_
long nPos; ko<u0SjF)u
%3b;`Oa
UdO(9Jc5^
public FileAccessI() throws IOException g~EN3~
{ k{\wjaf)
this("",0); RP[^1
} WV5z~[
)S?.YCv?
}_Y&kaM
public FileAccessI(String sName,long nPos) throws IOException o]T-7Gs4p
{ VWhq+8z
oSavedFile = new RandomAccessFile(sName,"rw"); Ac^hZ.qPz
this.nPos = nPos; T:FaD V{
oSavedFile.seek(nPos); ,~8&0p
} B|9[DNd
m\*;Fx
@M( hyS&on
public synchronized int write(byte[] b,int nStart,int nLen) T{WJf-pI
{ eBT+|
int n = -1; !m]_tB
try{ iA.:{^_)09
oSavedFile.write(b,nStart,nLen); C2e.RTxc
n = nLen; z`]sWi F0
} T-MC|>pv
catch(IOException e) X|&v]mJ
{ UP<B>Y1a
e.printStackTrace (); B1^9mV'O
} ,zF^^,lO7
(#e,tu
C"SG':
return n; itYTV?bd
} (V(8E%<c
x)+ q$FB
op8[8pt%
} !)r1zSY"g
"udA-;!@&
5,_DM
/* z:1"d R
**SiteInfoBean.java 1S{AGgls5
*/ z(!K8 T
package NetFox; ,gO(zI-1
,7:?Du}
Sdzl[K/}
public class SiteInfoBean { 2 xE+"?0
Cfr2~w
99GK6}~TGm
private String sSiteURL; //Site's URL ptQCqQ1_d
private String sFilePath; //Saved File's Path fK/|0@B8
private String sFileName; //Saved File's Name *-eDUT|O
private int nSplitter; //Count of Splited Downloading File A)9F_;BY
.;J6)h
r=gF&Og,?
public SiteInfoBean() vJ?j#Ch
{//nSplitter的缺省值为5 JZup} {a
//default value of nSplitter is 5 g0-~%A,
this("","","",5); B<{Yj}..
} 'z9}I #
o}b_`O
"}Oj N\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U[O7}Nsb"
{ T9NTL\;
sSiteURL= sURL; 'H8b+
sFilePath = sPath; h+DK .$
sFileName = sName; ,p' ;Xg6ez
this.nSplitter = nSpiltter; ,a34=,
bLsN?_jy
.+A2\F.^
} i%GNmD
rM0Idc.$&&
N{&Hq4^c
public String getSSiteURL() R ~?9+
{ o`M.v[O
return sSiteURL; ^wlo;.8Y
} Z,I0<ecaD
HSj=g}r
Yn5a4
public void setSSiteURL(String value) ja&S^B^@
{ ` InBhU>
sSiteURL = value; r7+Ytr
} 24I\smO
=rN_8&
tjJi|
public String getSFilePath() z7!@^!r
{ 2*@@Bw.XA
return sFilePath; u= Vt3%q
} 7v V~O@JP
wBz5_ OFVw
#k t+ )>
public void setSFilePath(String value) "R0(!3
{ ,CIsZ1[VS
sFilePath = value; bL2b^UB~%
} mvu$
`s8!zy+
hQ}y(2A.XI
public String getSFileName() {JtfEna
{ 9'0v]ar
return sFileName; ~=t K17i
} 8Z>=sUMQ
aa&\HDh*
&%;K_asV;
public void setSFileName(String value) ^Is#_Z|
{ o)+Uyl
sFileName = value; :+Tvq,/"
} W[qQDn!r
T:g=P@
lNx:_g:SrZ
public int getNSplitter() -] `OaL!
{ H'?dsc
return nSplitter; uF\ ;m.
} -DWnDku8=
;uaZp.<um&
F/:Jp3@
public void setNSplitter(int nCount) K?6#jT6#
{ g_e_L39
nSplitter = nCount; HME`7dw?
} ^v&)z,
} >#|%y>g .o
6tN!]
'a=' (,%
/* =6xxZy[
**Utility.java @QAI 0ZY
*/ =-;J2Qlg6
package NetFox; Lz=GA?lk[\
c}mWAZ=wF
hIFfvUl
public class Utility { x%%OgO+>
h`pXUnEZ
}o7"2hht
public Utility() ,rWej;CzN
{ Yl"l|2 :
M"E7=J
#_'| TT>p#
} G'(8/os{
c63yJqiW
//线程睡眠 %Iv*u sXP
public static void sleep(int nSecond) xnPi'?A]
{ C]NL9Gq`
try{ >tTu1#t
Thread.sleep(nSecond); L]{1@~E:q
} u9D#5NvGs
catch(Exception e) QN^AihsPi
{ qORRpWyx&
e.printStackTrace (); D}]u9jS1
} v_I)eac z
} %OAvhutS
`l+ pk%
//日志 TyN]Pa
public static void log(String sMsg) p #Y2v
{ E@7);i5K
System.err.println(sMsg); =k:yBswi
} PEPf=sm
G }U'?p
o>Q=V0?
public static void log(int sMsg) UpS7>c7s
{ rvp#[RAaS}
System.err.println(sMsg); Wph@LRB]
} I6rB_~]h
} 'yNS(Bg=
lC'U3Q&
Ih^ziDcW
/* U$7]*#@&
**TestMethod.java 89\DS!\x9
*/ Xsd+5="{N
package NetFox; MP$9W)
PAS0 D #
ayrCLv
public class TestMethod { dT'd C
-d_7 q
|:,i
public TestMethod() giORc
{ ///xx/weblogic60b2_win.exe x`JhNAO>
try{ XB;C~:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >8.o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); AI#.G7'O
SiteFileFetch fileFetch = new SiteFileFetch(bean); D]+]Br8
fileFetch.start(); q}cm"lO$
} 2k M;7:
catch(Exception e){e.printStackTrace ();} %![3?|8~
D|D)782
RiiwsnjC
} ZK5 wZU
R3hyz~\x&
Dy|)u1?
public static void main(String[] args) >G}g=zy@
{ "ifv1KZ#
new TestMethod(); Y(B3M=j
} ndHUQ$/(
} W9:(P
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