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)); ws^ np
} 7J&4akT{9
for(int i=0;i<nEndPos.length-1;i++) q"_QQ~
{ pY$Q
nEndPos = nStartPos[i+1]; Zj4Uak
} GowH]MO
nEndPos[nEndPos.length-1] = nFileLength; jlg(drTo
} CVR3 A'
} 5rUdv}.
gltBC${7wZ
@ur+;IK$
//启动子线程 T9q-,w/j;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7j)8Djzp|
for(int i=0;i<nStartPos.length;i++) W`*r>`krVJ
{ /5AJ.r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r!{Up7uL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FU<Jp3<%
nStartPos,nEndPos,i); 7vj2 `+r.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .XhrCiZ
fileSplitterFetch.start(); 0Fr?^3h
} @AuO`I@p=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?b5^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <_KIK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -n5)w*b,
nEndPos = " + nFileLength); VOh4#%Vj
// fileSplitterFetch[nPos.length-1].start(); @$K"o7+]
F1Bq$*'N$w
y L~W.H
//等待子线程结束 -1@<=jX3_
//int count = 0; $ o#V#
//是否结束while循环 `pZm?}K
boolean breakWhile = false; fLAw12;^
;P&OX5~V
N$:8,9.z
while(!bStop) 1ZB"EQ
{ _8agtQ:<
write_nPos(); :S(ZzY Q
Utility.sleep(500); n@[O|?S
breakWhile = true; %GIr&V4|
MR.'t9m2L
"Os_vlapHo
for(int i=0;i<nStartPos.length;i++) ps DetP
{ u,Kly<0j
if(!fileSplitterFetch.bDownOver) S?BG_J6A7
{ 26x[X.C:
breakWhile = false; 1 I",L&S1
break; Ef13Q]9|
} &UlWCOo8
} YkQd
if(breakWhile) eO[b1]WLP
break; g95`.V}
@2v_pJy^
2gVm9gAHUd
//count++; 2SR:FUV/
//if(count>4) t#eTV@-
// siteStop(); !m?-!:
} d9|<@A
.Rf_Cl
"`1bA"E
System.err.println("文件下载结束！"); P J[`|
} 'a.qu9PJ
catch(Exception e){e.printStackTrace ();} 2Q:+_v
} {3vNPQJ
fL7xq$K
0%I=d
//获得文件长度 I4?5K@a
public long getFileSize() D*|Bb?
{ ! #2{hQRu
int nFileLength = -1; ayF\nk4b
try{ .y:U&Rw4
URL url = new URL(siteInfoBean.getSSiteURL()); \mlqO[ S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0h7r&t%YsV
httpConnection.setRequestProperty("User-Agent","NetFox"); >!)DM]Ri
Jma1N;d
`%WU8Yv
int responseCode=httpConnection.getResponseCode(); >Wg hn:^
if(responseCode>=400) ls)%c
{ :tv,]05t
processErrorCode(responseCode); >`ZyG5
return -2; //-2 represent access is error | (_
} HT1!5
A1zjPG&]
Bo%NFB;
String sHeader; ]~hk6kS8Q
!0mI;~q|F
U}j0D2
for(int i=1;;i++) -_eLf#3
{ $5Ff1{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ))'<_nD
//Utility.log(in.readLine()); ~zNAbaC+>t
sHeader=httpConnection.getHeaderFieldKey(i); XAL1|]S
if(sHeader!=null) iTU5l5Uz
{ fkNbS
if(sHeader.equals("Content-Length")) xe&i^+i
{ 3WIk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O/(xj2~$J
break; vTw>JNVI
} GYUn6P
} yd`mG{Z
else 'u<juFr
break; y;@:ulv[
} "o}+Ciul
} =P #]
catch(IOException e){e.printStackTrace ();} Aj+F |l
catch(Exception e){e.printStackTrace ();} 1Nd2{(
7g}w+p>
x>`%DwoRI
Utility.log(nFileLength); (mtk 4
9o:Lz5o
t"/q]G5
return nFileLength; HBx=\%;n
} #';:2Nyq
xbYi.
dT1H
//保存下载信息（文件指针位置） {8,J@9NU
private void write_nPos() Y#$%iF
{ B%+T2=&$7
try{ +@iA;2&
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]^K4i)\
output.writeInt(nStartPos.length); >%8KK|V{
for(int i=0;i<nStartPos.length;i++) E#t>Qn
{ =]Jd9]vi
// output.writeLong(nPos); .$)
output.writeLong(fileSplitterFetch.nStartPos); 2Ny"O.0h
output.writeLong(fileSplitterFetch.nEndPos); 7,9=uk>0\
} WKa~[j|-K
output.close(); R/>@+
} a\YV3NJ/A
catch(IOException e){e.printStackTrace ();} PQ$%H>{
catch(Exception e){e.printStackTrace ();} +-CtjhoS
} ;)^`3`
N7 $I^?<
EV@X*| w
//读取保存的下载信息（文件指针位置） V~;1IQd{
private void read_nPos() ve2u=eQ1
{ bTs?!~q
try{ yT9@!]^L
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); % 0+j?>#X
int nCount = input.readInt(); i5?q,_
nStartPos = new long[nCount]; R>mmoG}MQ[
nEndPos = new long[nCount]; ]R9HyCl&a6
for(int i=0;i<nStartPos.length;i++) !lc[
{ _1!OlQ
nStartPos = input.readLong(); R)ITy!z
nEndPos = input.readLong(); b-Q>({=i
} !.(P~j][
input.close(); I(7NQ8Hx
} Hm'=aff6A
catch(IOException e){e.printStackTrace ();} \WB<86+z
catch(Exception e){e.printStackTrace ();} 3Xy-r=N.l
} 3c6b6
oij}'|/Jc
)6,=f.%
private void processErrorCode(int nErrorCode) z]`k#O%%)
{ .I0qGg
System.err.println("Error Code : " + nErrorCode); Jk=I^%~
} _k~KZ;l
l &5QZI0I
v"XGCi91L
//停止文件下载 Ayw ;N
public void siteStop() fbKkq.w
{ !1{e|p 7
bStop = true; q0R -7O(
for(int i=0;i<nStartPos.length;i++) EkNunCls
fileSplitterFetch.splitterStop(); @? QoF#D
jeH~<t{
E`de7
} n'kG] Q
} !1 8clL
//负责部分文件的抓取 aa#Y=%^
**FileSplitterFetch.java =sJ7=39
*/ H0`]V6+<f
package NetFox; -0{r>,&Mm
#S*/bao#
9V@V6TvW>&
import java.io.*; G5aieD.#
import java.net.*; K<qk.~ S
+:!7L=N#
q[W 0 N>
public class FileSplitterFetch extends Thread { Q&=w_Wc
jun_QiU:2
1A G<$d5U|
String sURL; //File URL $ig0j`
long nStartPos; //File Snippet Start Position D"rK(
long nEndPos; //File Snippet End Position T)TfB(
int nThreadID; //Thread's ID 8xV9.4S
boolean bDownOver = false; //Downing is over $r8 ^0ZRr
boolean bStop = false; //Stop identical "(z5{z?S
FileAccessI fileAccessI = null; //File Access interface vyX\'r.~7
r6} |hpJ8
Et/\xL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @As[k2
{ *%fi/bimG
this.sURL = sURL; v>Yb/{A
this.nStartPos = nStart; vK\%%H
this.nEndPos = nEnd; Y^7$t^&
nThreadID = id; !1DKLQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ``Dq
} s!&#c`=
9c#+qH
{kCw+eXn?
public void run() p~^D\jR.
{ 'H&2HXw&2
while(nStartPos < nEndPos && !bStop) ]#l/2V1
{ o(LFh[
PHXZ=A+
&cHV7
try{ `c5"d
URL url = new URL(sURL); Q$1bWUS&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Raxrb=7
httpConnection.setRequestProperty("User-Agent","NetFox"); G{ sOR
String sProperty = "bytes="+nStartPos+"-"; ^*8G8'k;$
httpConnection.setRequestProperty("RANGE",sProperty); 4C-jlm)V
Utility.log(sProperty); E2@65b$
Q<'nE
Ba*,-i3ZK
InputStream input = httpConnection.getInputStream(); m4&h>9. 8
//logResponseHead(httpConnection); gL[yA?GoM
"2P&X
WEQ1 Seq
byte[] b = new byte[1024]; m~P CB_ifW
int nRead; V4P; 5[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gh}LlX!w
{ ,5kKimTt
nStartPos += fileAccessI.write(b,0,nRead); 7;sj%U^'l
//if(nThreadID == 1) bRJMYs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5eoska#y
} /!Wu D\B
}Q?c"H!/
Hh-+/sO~"
Utility.log("Thread " + nThreadID + " is over!"); %?uc><&?e
bDownOver = true; ;WM"cJo9
//nPos = fileAccessI.write (b,0,nRead); $Ifmc`r1
} cU@SIJ)
catch(Exception e){e.printStackTrace ();} [}/LD3
} u7\J\r4,+
} /#-C4"|
R)z4n
{QZUDPPR
//打印回应的头信息 *4xat:@{{
public void logResponseHead(HttpURLConnection con) SHbtWq}T
{ ~\.w^*$#Y
for(int i=1;;i++) ^3{TZ=_;|
{ N#7QzB9]
String header=con.getHeaderFieldKey(i); #PanfYR
if(header!=null) e8]\U/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8V)^R(\;
Utility.log(header+" : "+con.getHeaderField(header)); r>"
else *x])Y~oQ
break; ?^$MRa:D
} oA7;.:3
} V7[zAq
LbG_z =A
J'fQW<T4wU
public void splitterStop() .0iQad&duh
{ U.XNv-M
bStop = true; e~@[18
} 'fF;(?
wX[8A/JPD
)V ;mwT!Q
} MHai%E
n\5RAIg
r77PQQDT
/* 'u_t<F]b
**FileAccess.java Ikiib WQL+
*//文件访问(定位，写) T/xp?Vq6/
package NetFox; K]|> Et`
import java.io.*; bKQ"ax>6p
rN<b?KE
:GW&O /Yo
public class FileAccessI implements Serializable{ 1_ C]*p
%1O[i4s:-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H5]^ 6 HwX
RandomAccessFile oSavedFile; 2eC(Ijq[a
long nPos; !V\Q<So<
T G{k0cdOT
ZAUQJS 91E
public FileAccessI() throws IOException 92d6U2T4&
{ 4Hn`'+b
this("",0); no]z1D
} ks97k8B
80&.JP.
TJ'[--
public FileAccessI(String sName,long nPos) throws IOException +$(2:S*r
{ K+8-9$w6
oSavedFile = new RandomAccessFile(sName,"rw"); Q7C;1aO
this.nPos = nPos; vR=6pl$|~~
oSavedFile.seek(nPos); f=!VsR2o
} {g~bQ2wDC
z=_Ef3`M
;VNMD 6H
public synchronized int write(byte[] b,int nStart,int nLen) Nl9I*x^e
{ 7&"n`@(.!
int n = -1; }X_;X_\3;'
try{ T4 N~(Fi)
oSavedFile.write(b,nStart,nLen); R8UYP=Kp
n = nLen; mp?78_I)
} 3=$q
catch(IOException e) >sjhA|gXk
{ /K{9OT@>
e.printStackTrace (); ""h)LUrl
} )a3J9a;ZS0
,H2D
E+tB&
return n; N, *m ,
} D?,#aB"
M$d%p6Cv
G4;3cT3'
} aKlUX
Cb@3M"1:
1q3( @D5~+
/* R:AA,^Z
**SiteInfoBean.java 1>Dl\czn
*/ 5"]~oPK
package NetFox; P"?FnTbv[
7Wa?$6d
pge++Di
public class SiteInfoBean { ?@t d
pD2<fP_
,7)C"
private String sSiteURL; //Site's URL RQB]/D\BO
private String sFilePath; //Saved File's Path Gqcz<=/
private String sFileName; //Saved File's Name L9ap(
private int nSplitter; //Count of Splited Downloading File zT|)uP*
9cx =@
o/ mF#
public SiteInfoBean() :BukUket1e
{//nSplitter的缺省值为5 he-Ji
//default value of nSplitter is 5 +"}=d3E6
this("","","",5); q4$+H{xB
} F3lw@b3])
GK}'R=
!W'Ui 9uX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~!d/8?!
{ y}K\%;`[a
sSiteURL= sURL; s(LT
sFilePath = sPath; ~i_Tw#}
sFileName = sName; 6vTo*8D
this.nSplitter = nSpiltter; ,prF6*g+WE
0\~Z5k`IT
q )lnS )
} FvuGup`w
$1zvgep
4E[!,zvl
public String getSSiteURL() LrV{j?2@
{ mNAY%Wn6k
return sSiteURL; 1b>C<\
} #4h+j%y[H
p|/j4@-h
NHgjRPz"
public void setSSiteURL(String value) n*'<uKpM
{ dj&}Gedy
sSiteURL = value; ZC4*{
} iH2n.M "
m&0"<V!H/B
"SoHt]%#
public String getSFilePath() 5ZPzPUa8~
{ Q2%QLM:.,
return sFilePath; ^t*x*m8
} !lmWb-v%36
qxJQPz
9H]Lpi^OH
public void setSFilePath(String value) b2&V
{ h2;z4
sFilePath = value; Dli^2hD
} Ld,5iBiO:
B 2.q3T
;#)mLsl
public String getSFileName() JH]K/sC>
{ s&{Qdf
return sFileName; Lj%{y.Rj
} q 'a
"?GebA
ZDYJhJ.
public void setSFileName(String value) Zz |MIGHm
{ 0ZPV'`KGp
sFileName = value; 9kY[j2,+
} X7|.T0{=x
.2\0~x""
4oXbPr>
public int getNSplitter() TE-;X,gDV_
{ )I@L+
return nSplitter; $H'X V"<o
} %YlTF\-
MYnH2w]
@gBE{)Fj
public void setNSplitter(int nCount) "x&C5l}n
{ z&3]%t `C
nSplitter = nCount; 1(GHCxA8G
} ^yKY'>T#d
} y9;#1:ic
qJT0Y/l:(
]&i+!$N_
/* 7TX,T|>9
**Utility.java VLg EX4
*/ *Wb=WM-.
package NetFox; )yb+M ez
SHqyvF
6=PiVwI
public class Utility { I7\ &Z q
&,-p',\-
#G,XDW2"w
public Utility() xwzT#DXGJ
{ Rh] P8
I(n* _bFq
re,.@${H
} a%J6f$A#
vU/ D7
//线程睡眠 FX,$_:f6Y
public static void sleep(int nSecond) _8h8Wtif
{ bn 4 &O
try{ 8]0:1 {@
Thread.sleep(nSecond); -Ubj6 t_K
} '3kcD7
catch(Exception e) MdhT!?
{ R/<=mZ
e.printStackTrace (); $)e:8jS=
} td(M#a-
} VKLU0*2R
~j,TVY
//日志 BSp$F WvT?
public static void log(String sMsg) Q)Dwq?
{ +~|AT+|iI
System.err.println(sMsg); 1}`LTPW9
} abY0)t
cvAtwQ'
}w!ps{*
public static void log(int sMsg) ":d*dl
{ jgvh[@uB?
System.err.println(sMsg); uJ'9R`E ]1
} A1,4kqmE
} B$`lYDqaG
gf$HuCh|
-%uy63LbHF
/* 5&4F,v[zp
**TestMethod.java qZG-Lh
*/ 4&}\BU*
package NetFox; dB|Te"6
u2`xC4>c
8g5V,3_6
public class TestMethod { gB CC
.Y/-8H-3v
m(3);)d
public TestMethod() 4IGxI7~27#
{ ///xx/weblogic60b2_win.exe T=? bdIl
try{ .{N\<01
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )Ul&1UYA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lfMH1llx
SiteFileFetch fileFetch = new SiteFileFetch(bean); .g-3e"@
fileFetch.start(); {u]CHN`%Z
} TSyzdnMvz
catch(Exception e){e.printStackTrace ();} o#d$[oa
8)Tj H'
WX*cICb5
} mvf _@2^
hrlCKL&
O~Uw&Bq
public static void main(String[] args) VA]ZR+m
{ @bQ!zCI
new TestMethod(); k`IrZHMw
} E2yz=7sv5
} G(i\'#5+
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