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)); l!V| T?
} +{i"G,3
for(int i=0;i<nEndPos.length-1;i++) P3ev4DL
{ N%|Vzc
nEndPos = nStartPos[i+1]; yPG\ &Bo
} ?V:]u3
nEndPos[nEndPos.length-1] = nFileLength; IYg3ve`x
} @^6OV)
} !_H8Q}a
NG!cEo:2aa
lWw!+[<:q1
//启动子线程 Yk@s"qm3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G^@Jgx3n
for(int i=0;i<nStartPos.length;i++) 8421-c6y>
{ HT=Am
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q[Sd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9iddanQA
nStartPos,nEndPos,i); .P:f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IH5} Az
fileSplitterFetch.start(); r2F
} UEQ'D9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S]%U]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1L=Qg4 H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Vt)\[Tl~
nEndPos = " + nFileLength); Fp6[W5>(-
// fileSplitterFetch[nPos.length-1].start(); *5_8\7d
-1r&s
""v`0OP&J
//等待子线程结束 H0b6ZA%n
//int count = 0; kPX2e h
//是否结束while循环 LVFsd6:h
boolean breakWhile = false; &J/4J
)C01fZhD
CBnouKc:
while(!bStop) r|\'9"@
{ +b,31
write_nPos(); &;h~JS=
Utility.sleep(500); PVS<QN%
breakWhile = true; azDC'.3{p
&c<}++'h
9<(K6Q
for(int i=0;i<nStartPos.length;i++) <X I35\^
{ $,QpSK`9i
if(!fileSplitterFetch.bDownOver) ^'u;e(AaE
{ IL>/PuZku
breakWhile = false; )Rhff$
break; 'D0X?2
} X!#i@V
} KIAe36.~
if(breakWhile) 97]a-)SA
break; PZ!dn%4jy
d7_g u
ZP63Alt
//count++; *e-ptgO
//if(count>4) EB29vHAt~
// siteStop(); Y7:Y{7E7
} Id.Z[owC`Y
8pq-nuf|K
Hr<C2p^a
System.err.println("文件下载结束！"); J%\~<_2ny
} 16[-3cJ T
catch(Exception e){e.printStackTrace ();} -#S)}NEn
} zOiY0`=
yK&*,J |
N,/BudFo
//获得文件长度 2%{YYT
public long getFileSize() .W@(nQ-<
{ =,AC%S_D~
int nFileLength = -1; &G pA1
try{ znQ'm^h
URL url = new URL(siteInfoBean.getSSiteURL()); 1~R$$P11[9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vhYMWfbY
httpConnection.setRequestProperty("User-Agent","NetFox"); ?}=-eJ(7e
Tbi]oB#
$/, BJ/9
int responseCode=httpConnection.getResponseCode(); 0j{F^rph
if(responseCode>=400) WG8iTVwx
{ OBI+<2`Oc
processErrorCode(responseCode); `\/toddUh[
return -2; //-2 represent access is error 43J\8WBn@
} zmB31' _
&& DD
BLL]^qN;Y
String sHeader; $>'")7z
+ %MO7vL
^nHB1"OCV
for(int i=1;;i++) c?!YFm
{ e$Xq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "w*+v
//Utility.log(in.readLine()); " K 8&{=
sHeader=httpConnection.getHeaderFieldKey(i); *%T)\\H2
if(sHeader!=null) cS D._"P
{ XOysgX0g
if(sHeader.equals("Content-Length")) YH)Opk
{ jFuC=6aF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2SDh0F
break; OuOk=
} ET,Q3X\Oe
} Z0[)u_<
else %s$rP
break; gEr4zae
} JcTp(fnW.~
} x],8yR)R
catch(IOException e){e.printStackTrace ();} ?w+ QbT
catch(Exception e){e.printStackTrace ();} lQV|U;~D
.O5LI35,
7$!`p,@we/
Utility.log(nFileLength); NXzU0
I?_E,.)[ I
`6a]|7|f
return nFileLength; UGhW0X3k
} xT9Yes&
LXHwX*`Y
.A3DFm3t
//保存下载信息（文件指针位置） _Ry_K3K
private void write_nPos() n?'d|h
{ rr|"r
try{ <Ctyht0c.
output = new DataOutputStream(new FileOutputStream(tmpFile)); \\=.6cg<K
output.writeInt(nStartPos.length); UdT&cG
for(int i=0;i<nStartPos.length;i++) I"Q#IvNw
{ +"]oc{W!
// output.writeLong(nPos); X'cf&>h
output.writeLong(fileSplitterFetch.nStartPos); +$>N]1
output.writeLong(fileSplitterFetch.nEndPos); '5'3_vM
} w[ Axs8N'
output.close(); nIfN"
} TE3*ktB{N
catch(IOException e){e.printStackTrace ();} YecT 96%
catch(Exception e){e.printStackTrace ();} C&=x3Cz
} /&CUspb
N<9w{zIK(
D9ANm"#
//读取保存的下载信息（文件指针位置） Tdg6kkJ
private void read_nPos() (~S<EUc$
{ A2Q[%A
try{ 2=>*O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H{ZLk,
int nCount = input.readInt(); Osnyd+dJY
nStartPos = new long[nCount]; :Df)"~/mO+
nEndPos = new long[nCount]; "X`RQ6~]>
for(int i=0;i<nStartPos.length;i++) )AOPiC$jL
{ 7'Lp8
nStartPos = input.readLong(); &]w#z=5SXi
nEndPos = input.readLong(); y =R aJm
} l{8CISO*
input.close(); P*0f~eu
} Y+FP
catch(IOException e){e.printStackTrace ();} lqF>=15
catch(Exception e){e.printStackTrace ();} 8$ic~eJ
} 5? Wg%@
hGvqT,'
rsWQHHkO
private void processErrorCode(int nErrorCode) Rfht\{N 7
{ f3!n$lj
System.err.println("Error Code : " + nErrorCode); V"O9n[|
} Vn'?3Eb<
~x'zX-@rC
zhX;6= X2
//停止文件下载 wS V@=)H\:
public void siteStop() mmHJh\2v
{ Q\|18wkW
bStop = true; Twx{' S
for(int i=0;i<nStartPos.length;i++) HcA[QBh
fileSplitterFetch.splitterStop(); )S2iIi;Bq
pajy#0 U
I]jX7.fx
} #7o0dE;Kg9
} /l^y}o %?
//负责部分文件的抓取 ilv_D~|
**FileSplitterFetch.java IP04l;p/
*/ '*4iqPR;
package NetFox; %*jGim~s
JA<~xo[Q9
S;8.yj-
import java.io.*; 7H%_sw5S.
import java.net.*; zka?cOmYF[
#&V5H{
t@)my[!
public class FileSplitterFetch extends Thread { d@ZoV
12lEs3
|<rfvsQ.
String sURL; //File URL Aq"PG}Ic
long nStartPos; //File Snippet Start Position g5}lLKT
long nEndPos; //File Snippet End Position MKC$;>i
int nThreadID; //Thread's ID &:No}6
boolean bDownOver = false; //Downing is over +*C^:^jA
boolean bStop = false; //Stop identical yp p4L|R
FileAccessI fileAccessI = null; //File Access interface K6hfauWd[
;g9%&
@h#Xix7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c|lU(Tf
{ hM>*a!)U
this.sURL = sURL; 4UD' %}>y
this.nStartPos = nStart; kwlC[G$j7
this.nEndPos = nEnd; GJ`UO
nThreadID = id; DWrbp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e!Br>^8l
} ~KRnr0
&Mj1CvCv
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public void run() 6e#wR/
{ cy3M^_5B<
while(nStartPos < nEndPos && !bStop) mgVML&^
{ 6m+W#]^
ln#\sA?iG
B+46.bIH
try{ JYV\oV{
URL url = new URL(sURL); fhRjYYGI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @.ZL7$|d
httpConnection.setRequestProperty("User-Agent","NetFox"); ~<,Sh~Ana.
String sProperty = "bytes="+nStartPos+"-"; -k{Jp/-D
httpConnection.setRequestProperty("RANGE",sProperty); yp+F<5o
Utility.log(sProperty); +"uwV1)b"
=dGKF`tR
A(+:S"|@
InputStream input = httpConnection.getInputStream(); PN &|8_
//logResponseHead(httpConnection); QNArZ6UQ
iBoEZEHjw
M&yqfb[
byte[] b = new byte[1024]; k[9A,N^lZB
int nRead; W:O0}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z0Xa_w=
{ "8HE^Po/pn
nStartPos += fileAccessI.write(b,0,nRead); _~A~+S}
//if(nThreadID == 1) B 8{ uR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %F J#uQXZ
} `6F+Rrn
d>!p=O`>{q
yX!#a>d"H
Utility.log("Thread " + nThreadID + " is over!"); S}7>RHe
bDownOver = true; 4j3oT)+8
//nPos = fileAccessI.write (b,0,nRead); /9_#U#vhY
} T~J?AKx
catch(Exception e){e.printStackTrace ();} uD(t`W"
} }bMWTT
} 1;Xgc@
V@Wcb$mgk
dJl^ADX[@
//打印回应的头信息 _M5Xk?e=
public void logResponseHead(HttpURLConnection con) 3eKQ<$w
{ %+wF"
for(int i=1;;i++) f1Zt?=
{ @^?XaU
String header=con.getHeaderFieldKey(i); wL2XNdo}<
if(header!=null) p)/ p!d[T/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^,V[nfQR
Utility.log(header+" : "+con.getHeaderField(header)); o.^y1mH'
else ,%hj cGX11
break; 8i:[:Z
} GBbhar},g
} &p"(-
JD~aUB%
c3k|G<C2
public void splitterStop() R0<< f]
{ sKfXg`0
bStop = true; VPd,]]S5(
} 70Ka!
M!{'ED
>&Fa(o;*
} l2&hBacT
6c<ezEJ
"l,UOv c
/* >n!ni(
**FileAccess.java j|K.i/
*//文件访问(定位，写) 7&6Y
package NetFox; @J vZ[T/
import java.io.*; DU{bonR`
D;js.ZF
f\K#>u* Q
public class FileAccessI implements Serializable{ o4)hxs
aqr!oxn?t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^M|K;jt>
RandomAccessFile oSavedFile; W9R`A
long nPos; & _K*kI:
.nZ3kT`
nyhMnp#<
public FileAccessI() throws IOException X\sm[_I
{ T[.[ g/`
this("",0); 1^{`lK~2
} x / XkD]Hq
nNn56&N]
'b[0ci:
public FileAccessI(String sName,long nPos) throws IOException MF.[8Zb
{ (5`T+pAsV
oSavedFile = new RandomAccessFile(sName,"rw"); 8tQ|-l*
this.nPos = nPos; /f3m)pT
oSavedFile.seek(nPos); s AE9<(g&@
} 3jPB#%F
(pYYkR"
t26ij`V
public synchronized int write(byte[] b,int nStart,int nLen) F?4Sz#
{ ybvI?#
int n = -1; e4.&aIC[
try{ cY{Nos
oSavedFile.write(b,nStart,nLen); =nhzMU9c\y
n = nLen; NWKi ()nA%
} {ZqQ!!b
catch(IOException e) pm]fQuq
{ ?`P2'i<b
e.printStackTrace (); y/R+$h(%
} 6?SFNDQ"C
0HbJKix!
'ZnIRE,N
return n; "!q?P" @C
} frH)_YJ%
!_^g8^>2(
r95zP]T
} qrDcL>Hrn
}gCHQ;U7`
4e9E' "8%
/* fIyPFqf7w)
**SiteInfoBean.java :s*>W$Wp4
*/ [ud|dwP"
package NetFox; ;.s:X
']?=[`#NL
`P.CNYR<J
public class SiteInfoBean { CEqZ:c
oVkr3KZ
}1m_o@{3P
private String sSiteURL; //Site's URL OCW+?B;
private String sFilePath; //Saved File's Path n`<U"$*
private String sFileName; //Saved File's Name &=zU611,
private int nSplitter; //Count of Splited Downloading File :_H>SR:
>&hX&,hG
;$;rD0i|
public SiteInfoBean() c]v +
{//nSplitter的缺省值为5 @^CG[:|
//default value of nSplitter is 5 M=%!IT
this("","","",5); !}q."%%J_%
} FpzP#;
F^rl$#pCS
^<;w+%[MT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kfCKhx
{ k7Oy5$##
sSiteURL= sURL; l* Y[^'
sFilePath = sPath; :t>Q:mX(N
sFileName = sName; 7@P656{
this.nSplitter = nSpiltter; #!d]PH746
e\.HWV]I
*<k&#D"m
} K:w]>a
t/ eo]
h,]+>`b
public String getSSiteURL() IJIQ" s
{ ':sTd^V
return sSiteURL; \`gEu{
} Tc_do"uU
8.2`~'V
A^g>fv
public void setSSiteURL(String value) CJA+v-
{ ohplj`X[21
sSiteURL = value; `[@VxGy_
} 0||F`24
o^PuhVu
k<Oy%+C
public String getSFilePath() p1^0{ILx
{ M5u_2;3
return sFilePath; \n(ROf^'
} 8KKz5\kn7
GLcd9|H
`Sx.|`x8
public void setSFilePath(String value) b[0S=e G
{ yM|g|;U
sFilePath = value; pz @km
} J{!'f| J
[Q:f-<nH
DO%Pwfkd
public String getSFileName() ol#yjrv
{ 4y>(RrVG
return sFileName; raF] k0{
} 6Ty3e|do
+9_,w bF
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public void setSFileName(String value) 6lZGcRO
{ m2ox8(sd
sFileName = value; Se/ss!If
} $^IjFdD
%GVN4y&
369Zu4|u
public int getNSplitter() _j>L4bT
{ )r pD2H
return nSplitter; ]Y=S
} 5f{wJb2
{RJ52Gx(
2$Wo&Q^_
public void setNSplitter(int nCount) `OBl:e
{ <dS5|||
nSplitter = nCount; F#KF6)P
} _1\poAy
} q55M8B 4w
c l9$g7
I<KCt2:X
/* ;xI0\a7
**Utility.java Y=|CPE%V
*/ #XfT1
package NetFox; ILNXaJ'0a
s4N,^_j
'?b\F~$8
public class Utility { E;$$+rA
oo\IS\
r;$r=Ufr
public Utility() wZ O@J|
{ )u-ns5
X= SG
Zq^^|[)bA
} nqrDT1b**
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//线程睡眠 AT-0}9z{
public static void sleep(int nSecond) `{Hb2 }L5
{ qA04Vc[2
try{ <347 C{q
Thread.sleep(nSecond); *0lt$F$~b
} t={poQC~
catch(Exception e) g4i #1V=
{ 2nJYS2mT7
e.printStackTrace (); ["<5?!bU
} A_aO}oBX
} $@68=
y>4p~
//日志 t Z+0}d
public static void log(String sMsg) 75<el.'H
{ {({ R:!c
System.err.println(sMsg); Nz}|%.GP"
} }!Xf&c{7{
tD865gi
Cy]"
public static void log(int sMsg) 3Nc'3NPQ'
{ 2lF WW(
System.err.println(sMsg); gNG.l
} ,#=eu85'
} g~eJ YS,
e<kpcF5{\
t`h_+p%>
/* ?U=mcdqd
**TestMethod.java .vN)A *
*/ ]Qh[%GD
package NetFox; D\@e{.$MZ|
9fCiLlI
xP XoJN
public class TestMethod { ?56~yQF/2
k>7gy?Y!K<
0kkRK*fp}x
public TestMethod() "4KkKi
{ ///xx/weblogic60b2_win.exe ,"x23=]
try{ )j]gm i"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2*N&q|ED
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z3OZPxm
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?a*fy}A|
fileFetch.start(); 7YoofI
} d&O'r[S
catch(Exception e){e.printStackTrace ();} tq2-.]Y@U
M-{b
,w,ENU0~f
} :y4)qF
K-N]h
ZD$-V3e`
public static void main(String[] args) "bv,I-\
{ v(i1Z}*b
new TestMethod(); SH .9!lQv
} }qG?Vmq*R[
} 7f.4/x^
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