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)); 4w$_]ke
} x/mp=
for(int i=0;i<nEndPos.length-1;i++) 9}P"^N
{ 6f)2F< 7
nEndPos = nStartPos[i+1]; >#(n"RCHf
} $t/rOo9cV
nEndPos[nEndPos.length-1] = nFileLength; S%mfs!E>
} 1n=_y o
} {Wv%zA*8
~i0R^qfr
d=3'?l`
//启动子线程 b]Z@^<_E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; izZ=d5+K
for(int i=0;i<nStartPos.length;i++) /)>S<X
{ {i [y9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8g~EL{'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =!b6FjsiG
nStartPos,nEndPos,i); _.V?A*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oPQtGl p
fileSplitterFetch.start(); BR5BJX
} J CGC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;_?MX/w|&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )2e#HBnH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )?aaBaN$
nEndPos = " + nFileLength); 'UU\4M
// fileSplitterFetch[nPos.length-1].start(); 0CExY9@Wq
g);^NAA
"3CJUr:Q
//等待子线程结束 Wp0 Dq(
//int count = 0; O9M{ ).
//是否结束while循环 [bz T&o
boolean breakWhile = false; s +s" MI
s)J(/
!CTxVLl"F
while(!bStop) ~Bi_7 Q
{ ]< l6s
write_nPos(); Z.PBu|Kx
Utility.sleep(500); 'tgKe!-@
breakWhile = true; NAC_pM&B
)cJ#-M2
wK_]/Q-L
for(int i=0;i<nStartPos.length;i++) 0%Ll
{ J:*-gwv9*m
if(!fileSplitterFetch.bDownOver) (N-RIk73/O
{ feM6K!fL`
breakWhile = false; kRJ4-n^@><
break; 2B0W~x2=
} "r4AY
} 7cDU2l
if(breakWhile) op2Of<{h
break; BaI $S>/Q
*|.0Myjo
,_.I\EY[
//count++; Bq\F?zk<
//if(count>4) %8~Q!=*Iq
// siteStop(); f"[J"j8
} IY'=DePd
4S"\~><
^nJyo:DO;
System.err.println("文件下载结束！"); } p FQRSOZ
} f 3V Dv9(
catch(Exception e){e.printStackTrace ();} {6;9b-a]
} \uqjs+
(_kp{0r#
C&LBr|
//获得文件长度 M-L2w"
public long getFileSize() }"vW4
{ \J..*,'
int nFileLength = -1; j`'`)3f
try{ )~4II.`%^
URL url = new URL(siteInfoBean.getSSiteURL()); u@'0Vk0zGH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U@ ?LP
httpConnection.setRequestProperty("User-Agent","NetFox"); G@FI0\t
z?/1Kj}xG
#4MBoN(3
int responseCode=httpConnection.getResponseCode(); .;y#
if(responseCode>=400) O<PO^pi
{ ]xC#rwHUC
processErrorCode(responseCode); jUv!9Y}F
return -2; //-2 represent access is error `g8E1-]l
} ~vmdXR`'T
1_fZm+oW!
'j^xbikr
String sHeader; mpAR7AG6
C*U'~qRK
8`4<R6]LKB
for(int i=1;;i++) Y$N)^=7
{ {,*"3O:\:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4c oJRqf=
//Utility.log(in.readLine()); !CXt*/~
sHeader=httpConnection.getHeaderFieldKey(i); z,qRcO&
if(sHeader!=null) NaVQ9ku7VW
{ pi=-#g(2
if(sHeader.equals("Content-Length")) "|;:>{JC
{ LmlXMia
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3iw{SEY
break; }X x(^Zh
} L;gO;vO
} 7g R@$(1Z
else l"\~yNgk
break; 1h6^>()^
} {x'GJtpb
} 2*(Z==XC7
catch(IOException e){e.printStackTrace ();} NCxqh<
catch(Exception e){e.printStackTrace ();} `:P
iXyO(w4D
&] \X]p
Utility.log(nFileLength); C6O8RHg
[M.f-x:
W@yJAQ
return nFileLength; 763+uFx^
} Bo<>e~6P
8$(Dz]v|[&
lKEkXO
//保存下载信息（文件指针位置） PW3GL3+
private void write_nPos() d Le-nF
{ Vy_2.
try{ nXjPx@
output = new DataOutputStream(new FileOutputStream(tmpFile)); :4^\3~i1X
output.writeInt(nStartPos.length); B||;'
for(int i=0;i<nStartPos.length;i++) }I@L}f5N
{ Cy*|&=>j
// output.writeLong(nPos); b;)~wU=
output.writeLong(fileSplitterFetch.nStartPos); F)z;Z6{t4
output.writeLong(fileSplitterFetch.nEndPos); ,gL9?Wz
} ?$e9<lsQq)
output.close(); *^([ ~[
} )xb|3&+W
catch(IOException e){e.printStackTrace ();} Q}S_%I}u:
catch(Exception e){e.printStackTrace ();} TYI7<-Mp:[
} {EdH$l>94
Y?ez9o:/#
PMfkA!.Y
//读取保存的下载信息（文件指针位置） CgzD$`~
private void read_nPos() Q5%#^ZdsTd
{ CRbdAqofV
try{ 0flg=U9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E~LTb) !
int nCount = input.readInt(); &Q}*+Y]G
nStartPos = new long[nCount]; ~EK'&Y"1
nEndPos = new long[nCount]; _-5,zPR
for(int i=0;i<nStartPos.length;i++) :>itXD!
{ RxMH!^
nStartPos = input.readLong(); Jvun?J m
nEndPos = input.readLong(); ;/j= Ny{9
} ZNYH#mJX*
input.close(); Fq9Q+RNMZL
} B75k^ohfj
catch(IOException e){e.printStackTrace ();} +:3*
catch(Exception e){e.printStackTrace ();} Q:ezifQ
} 1Z{ZV.!
YDGS}~m~Q
5wUUx#
private void processErrorCode(int nErrorCode) Agrp(i"\@
{ @y31NH(
System.err.println("Error Code : " + nErrorCode); Tr^nkD{
} QMEcQV>
=}PdH`S
:{(w3<i
//停止文件下载 G<M:Ak+~
public void siteStop() W d0NT@
{ *Sh^J+j
bStop = true; M4xi1M#%
for(int i=0;i<nStartPos.length;i++) Jjl`_X$CB
fileSplitterFetch.splitterStop(); :UJa&$)
fr!Pj(Q1
f@co<iA
} HNL42\Kz!
} Y'e eA 2O
//负责部分文件的抓取 sZ?mP;Q
**FileSplitterFetch.java JF/,K"J
*/ ![f ![l
package NetFox; J~(Wf%jM~
H~ u[3LQz
7)%+=@
import java.io.*; .CSS}4
import java.net.*; hQNe;R5
`-3o+ID\
_e9:me5d"$
public class FileSplitterFetch extends Thread { kF>o.uSV
(LHp%LaZ\;
jmg!Ml
String sURL; //File URL e*j.
long nStartPos; //File Snippet Start Position -Z-IF#%
long nEndPos; //File Snippet End Position 1wW)tNKIF
int nThreadID; //Thread's ID rxme(9M
boolean bDownOver = false; //Downing is over l1]p'Liuu
boolean bStop = false; //Stop identical {,OS-g
FileAccessI fileAccessI = null; //File Access interface z6py"J@
7Ol}EPf#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BnRN;bu
{ %& _V0R\k
this.sURL = sURL; .@Ut?G
this.nStartPos = nStart; !`bio cA
this.nEndPos = nEnd; jp' K%P
nThreadID = id; g/CxXSv@0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1N2,mo?2
} |y<),j6
6oSQQhge
m?HZ;
public void run() OGiV{9U
{ wM[~2C=vx
while(nStartPos < nEndPos && !bStop) }3R13
{ i@NqC;~;
;WL1B
'Pvm8t
try{ 1}ZKc=Pfu
URL url = new URL(sURL); ?OdJqw0,G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (Toq^+`c
httpConnection.setRequestProperty("User-Agent","NetFox"); PM":Vd/
String sProperty = "bytes="+nStartPos+"-"; D|qk_2R%
httpConnection.setRequestProperty("RANGE",sProperty); {K#NB_*To
Utility.log(sProperty); -G,^1AL>
}bU8G '
W0jZOP5_.$
InputStream input = httpConnection.getInputStream(); T!W~n ZC
//logResponseHead(httpConnection); )rLMIk
8vk..!7n}
#GaxZ
byte[] b = new byte[1024]; e4OeoQ@ >
int nRead; D}3XFuZs_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VGL#!4wK
{ 9dh>l!2
nStartPos += fileAccessI.write(b,0,nRead); 1xf=_F0`&
//if(nThreadID == 1) A$g+K,.l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x( mE<UQN
} fQ>4MKLw=d
gqib:q;r
c^8o~K>w84
Utility.log("Thread " + nThreadID + " is over!"); N?dvuB
bDownOver = true; ZV}X'qGaq
//nPos = fileAccessI.write (b,0,nRead); m\/(w_/?
} ;jK#[*y
catch(Exception e){e.printStackTrace ();} Kt>X[o3m,
} 2S`?hxAL
} /\mKY%kyh
Q-rL$%~='
=\)IaZ
//打印回应的头信息 cD1o"bq
public void logResponseHead(HttpURLConnection con) ;evCW$G=
{ k&hc m
for(int i=1;;i++) \F,DA"K_
{ ngulcv
String header=con.getHeaderFieldKey(i); (UNtRz'=;
if(header!=null) 0h$GI"dR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $N$ FtpB
Utility.log(header+" : "+con.getHeaderField(header)); #y]3LC#)^G
else D}Ilyk_uUw
break; YC_3n5F%
} 'k&?DZ!
} dEM?~?
09M;}4ev&7
WKA'=,`v
public void splitterStop() FqA3{
{ r0m)j
bStop = true; z}}]jR\y?
} BX;5wKfA
P2n2Qt2
|c-LSs'\
} V'Y{v
.&,[,
QL"gWr`R
/* (U.**9b;
**FileAccess.java #`GbHxd
*//文件访问(定位，写) )&W|QH=AI
package NetFox; [UPNd!sy
import java.io.*; 7INk_2
ioIv=qGdiP
}IUP5O6
public class FileAccessI implements Serializable{ 5!fSW2N
twqFs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <Mgf]v.QS
RandomAccessFile oSavedFile; &B-[oqC?
long nPos; t\5c@j p
#dJ 2Q_2
.+#Lx;})
public FileAccessI() throws IOException Pw}_[[>$
{ d O A%F$Mk
this("",0); =xEk7'W6k
} c]Unbm^w
R$b,h
:B#EqeI
public FileAccessI(String sName,long nPos) throws IOException 5ouQQ)vA
{ t/:w1rw
oSavedFile = new RandomAccessFile(sName,"rw"); 9\51Z:>
this.nPos = nPos; ,zgNE*{Y"4
oSavedFile.seek(nPos); =Q?f96T
} .K9l*-e[=
\ZnN D1A
rnvQ<671W
public synchronized int write(byte[] b,int nStart,int nLen) :4;S"p
{ Fe="EDh
int n = -1; Z*bC#s?
try{ QP\yaPE
oSavedFile.write(b,nStart,nLen); D3?N<9g
n = nLen; :::>ro*R
} ?:}Pa<D&K
catch(IOException e) ?vu|o'$T,
{ w??c1)
e.printStackTrace (); O_CT+Ou
} '0Zm#g
xYT}>#[
N$'>XtO
return n; i| xt f
} P3$,ca'
IxP^i{/1?
AP@<r
} b?k4InXh
??I:H
px [~=$F
/* VG\mo?G
**SiteInfoBean.java "A7<XN<
*/ N*1
package NetFox; 0#`)Prop6
n!?r }n8
lM&UFEl-\
public class SiteInfoBean { t&pGQ
q2Rf@nt
P CsK()
private String sSiteURL; //Site's URL V2QW\2@$
private String sFilePath; //Saved File's Path poY8 )2
private String sFileName; //Saved File's Name [0(mFMC`
private int nSplitter; //Count of Splited Downloading File ]-EN/V
&E]"c]i+
82.HH5Z{
public SiteInfoBean() \P?--AIq<
{//nSplitter的缺省值为5 >Qk97we'9
//default value of nSplitter is 5 Wbd_aR (
this("","","",5); I}ndRDz[
} Re\o v x9
/1N)d?Pcl
h.D^1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %Y 2G
{ UhBz<>i;!
sSiteURL= sURL; /gX%ABmS
sFilePath = sPath; 8'%+G
sFileName = sName; &&*wmnWCS{
this.nSplitter = nSpiltter; q!@c_o
D0KELAcY
|QMT A5
} YZ{;%&rB
ME,duY/>Q
Ss+F9J
public String getSSiteURL() sHF%=Vu
{ R1~7F{FW
return sSiteURL; %WmZ ]@M
} I'P.K| "R
qWkx:-g]
x;*VCs
public void setSSiteURL(String value) gi '^qi2
{ F-i&M1\_
sSiteURL = value; " _mmR M
} @}Pw0vC
|B,dEx/uU
'2j~WUEmg
public String getSFilePath() w zdxw$E
{ pM,#wYL
return sFilePath; a3*.,%d
} 2pw>B%1WP)
)~G8 LZ
A03I-^0g+
public void setSFilePath(String value) cFe V?a
{ !(}OBZ[*
sFilePath = value; \?[O,A
} 0;'j!`l9
w:n(pLc<
(1OW6xtfG
public String getSFileName() \gjl^#;
{ _8Pmv$
return sFileName; P:jDB{
} #V,LNX)
L,tZh0
1mAUEQ!
public void setSFileName(String value) 3{I=.mUUm
{ se}pdL}
sFileName = value; #vnefIcBf
} /abmjV0
~D$#>'C#
Jx)~kK
public int getNSplitter() LNWqgIq
{ Xq[:GUnt
return nSplitter; NU BpIx&
} PEK.Kt\M
W` WLW8Qsw
tj`tLYOZ@-
public void setNSplitter(int nCount) AEiWL.*.
{ )zo#1$C-
nSplitter = nCount; -9hp+0 <
} |k/`WC6As.
} ~5x4?2
g|_HcaW
ly9x1`?$
/* r_{)?B
**Utility.java gK&5HTo
*/ V.O<|tl.
package NetFox; oHv{Y
*##QXyyg
9/@FADh
public class Utility { BT y]!%r'
|?4~T:
oAIY=z
public Utility() b|\{ !N]
{ H8(0.IR
FY_avW
\<0G kp
} 5i}CzA96
jV(xYA3
//线程睡眠 # CP9^R S
public static void sleep(int nSecond) ze#rYNvo/
{ 1Xk{(G<\
try{ 2tg/S=t}
Thread.sleep(nSecond); dXf]G6
} D;16}D
catch(Exception e) .b!OZ
{ YD0vfwh
e.printStackTrace (); !;xf>API
} (6b?ir~
} ,6y-.m7>
tkm~KLWV&7
//日志 <=5,(a5g
public static void log(String sMsg) -$sl!%HO%
{ 8.q13t!D
System.err.println(sMsg); 5p#o1I
} T_5*iwI
8o%<.]
#'G7mAoA
public static void log(int sMsg) r-1yJ
{ L~?,6
System.err.println(sMsg); gavQb3EP
} l\A}lC0?J
} eY6gb!5u
l"~h1xk~
/:*R -VdF
/* [7SI<xkv
**TestMethod.java &\WkJ}&PnA
*/ b3y,4ke"
package NetFox; lyOrM7Gs
H;b'"./
ATXx? b8h
public class TestMethod { y$r?t0
@'NaA SB
O)=73e\
public TestMethod() Hjo:;s
{ ///xx/weblogic60b2_win.exe q6m87O9
try{ JJbM)B@-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fO^EMy\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v0H>iKh7
SiteFileFetch fileFetch = new SiteFileFetch(bean); r,Y/4(.c7U
fileFetch.start(); u}@%70A
} u6bB5(s`&
catch(Exception e){e.printStackTrace ();} =vqE=:X6
RL]lt0O{
]( U%1
} 644hQW&W
6wvhvMkS
0F;(_2V-
public static void main(String[] args) /KJxn6
{ lG[ )8!:+
new TestMethod(); 2}xFv2X
} W0uM?J\O
} 7]HIE]#
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