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)); E"e<9
} iEG`+h'
for(int i=0;i<nEndPos.length-1;i++) _e<3 g9bj
{ ,4hQ#x
nEndPos = nStartPos[i+1]; UwuDs2 t
} >z*2Og#1
nEndPos[nEndPos.length-1] = nFileLength; Zs _Jn
} _q >>]{5
} B1]dub9
je6H}eWTC6
%a;N)1/
//启动子线程 Ij_Y+Mnl4:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \e%H5Wx
for(int i=0;i<nStartPos.length;i++) K~p\B
{ \K+LKa)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i?uJ<BdU[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^zPa^lo-
nStartPos,nEndPos,i); "oX@Z^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n22k<@y
fileSplitterFetch.start(); E\2|
} 0GW(?7ZC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =k#SQ/@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Yb8o`j+t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6$TE-l
nEndPos = " + nFileLength); _{z.Tu
// fileSplitterFetch[nPos.length-1].start(); ZzA4iT=KO
xy>~15
md_9bq/w
//等待子线程结束 PaPQ|Pwz
//int count = 0; [U_Su,
//是否结束while循环 +Z0@z^6\
boolean breakWhile = false; ZOGH.`
ek~bXy{O`
= 8F/]8_
while(!bStop) ?[>+'6
{ 1df}gG
write_nPos(); V_JM@VN}Kk
Utility.sleep(500); 9V*h:[6a(
breakWhile = true; 1<RB}M
"71@WLlN
:Hdn&a i
for(int i=0;i<nStartPos.length;i++) _ F&BSu
{ ;C=C`$Q
if(!fileSplitterFetch.bDownOver) FBpf_=(_1
{ 1*aw~nY0
breakWhile = false; zmvF#o
break; }ie\-V
} ]t-_.E )F
} Td%[ -
if(breakWhile) MY11 5%
break; ?5d7J,"<h
&UtsI@Mu
Id3i qAL
//count++; / $7E
//if(count>4) jRP.Je@t
// siteStop(); p`ai2`qC`
} J{"<Hgb
;C,D1_20Z
?k)(~Y&@p
System.err.println("文件下载结束！"); dLQV>oF
} HY[eo/nM1d
catch(Exception e){e.printStackTrace ();} Y@'ug N|[C
} $y~!ePKh
R1Jj 3k
9l9h*Pgt
//获得文件长度 gZQ,br*
public long getFileSize() |7XV!D!\g
{ tkrRdCq
int nFileLength = -1; .\1{>A
try{ 7XLz Ewa
URL url = new URL(siteInfoBean.getSSiteURL()); L=zt\L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v^_OX$=,
httpConnection.setRequestProperty("User-Agent","NetFox"); -z%| Jk
"NqB_?DT
|ho|Kl `=
int responseCode=httpConnection.getResponseCode(); 4#H~g @
if(responseCode>=400) (~t/8!7N
{ @m14x}H
processErrorCode(responseCode); /8 /2#`3R
return -2; //-2 represent access is error ,1+AfI
} I6}ineps
m}Z=m8
KrNu7/H
String sHeader; NbyVBl0=
Zr`pOUk!4
Z6G>j
for(int i=1;;i++) ~x`BV+R
{ r@;n \
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1muB* O
//Utility.log(in.readLine()); 9Tbi_6[
sHeader=httpConnection.getHeaderFieldKey(i); ^Y"c1f2
if(sHeader!=null) ]<\FtH
{ C^>txui8
if(sHeader.equals("Content-Length")) Ik_u34U
{ m4FT^^3yE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +[$d9
break; "W:#4@ F
} EN^C'n
} cTW3\S=
else 5v:c@n
break; [0v`E5
} MH;5gC@ `
} R{zAs?j
catch(IOException e){e.printStackTrace ();} Hk)IV"[R
catch(Exception e){e.printStackTrace ();} md8r"
'urn5[i
biZwxP3
Utility.log(nFileLength); {ir8n731p
NbPv>/r
o5(`7XV6D
return nFileLength; ,A`.u\f(:
} y8/ 7@qw
qi!Nv$e
%W!C
//保存下载信息（文件指针位置） HFV4S]U=
private void write_nPos() IBYRuaEB
{ M~ =Bln5
try{ $GI2rzh
output = new DataOutputStream(new FileOutputStream(tmpFile)); ROZOX$XM
output.writeInt(nStartPos.length); R7xKVS_MP
for(int i=0;i<nStartPos.length;i++) _&0_@
{ >^vyp!
// output.writeLong(nPos); 4{!7T
output.writeLong(fileSplitterFetch.nStartPos); L`v7|!X
output.writeLong(fileSplitterFetch.nEndPos); rdK=f<I]
} 0<3)K[m~H
output.close(); [v7)xV@c
} `Mj>t(
catch(IOException e){e.printStackTrace ();} ^{L/) Xy5
catch(Exception e){e.printStackTrace ();} 2%0J/]n\A"
} Eg&oAY.U
}A@op+0E
w9QY2v,U
//读取保存的下载信息（文件指针位置） y#%*aV}|B
private void read_nPos() ILsw'
{ {9(#X]'
try{ Kh{C$b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v6r,2Va/
int nCount = input.readInt(); BEn,py7
nStartPos = new long[nCount]; |etA2"r&
nEndPos = new long[nCount]; k%UE^
for(int i=0;i<nStartPos.length;i++) 19.+"H
{ y7)s0g>%H
nStartPos = input.readLong(); v;=F$3
nEndPos = input.readLong(); l/|bU9o /u
} $LxfdSa
input.close(); fTn
} eBw6k09C+
catch(IOException e){e.printStackTrace ();} r*e<`Is
catch(Exception e){e.printStackTrace ();} lFHj]%Y
} I)@b#V=
{<\[gm\X
nP9zTa
private void processErrorCode(int nErrorCode) Ns^[Hb[b'
{ '`.bmiM
System.err.println("Error Code : " + nErrorCode); (_2;}eg
} sn.Xvk%75
?OW!zE:
\EP<r
//停止文件下载 Aw]W-fx
public void siteStop() aTJs.y-I~
{ #dcfQ
bStop = true; xp+Z%0D
for(int i=0;i<nStartPos.length;i++) Tyc`U&
fileSplitterFetch.splitterStop(); }jF67c->
MiB"CcU
C_c*21X
} z: x|;Ps!
} <$#;J>{WV
//负责部分文件的抓取 x>Hg.%/c[
**FileSplitterFetch.java n\l$R!zr
*/ 9eA2v{!S
package NetFox; 5~AK+6Za
EfTuHg$pe
RtE2%d$JT
import java.io.*; @"B"*z-d
import java.net.*; t-, =sV
I-=H;6w7
JIw=Bs
public class FileSplitterFetch extends Thread { /hx|KC&:e
!KYX\HRW
fu}ZOPu
String sURL; //File URL }ioHSkCD
long nStartPos; //File Snippet Start Position 6xFvu7L_c;
long nEndPos; //File Snippet End Position s<}d)L(
int nThreadID; //Thread's ID "JHdF&
boolean bDownOver = false; //Downing is over @wzzI 7}C
boolean bStop = false; //Stop identical m[k@\xS4e
FileAccessI fileAccessI = null; //File Access interface U{^~X_?
,qo"i7c{:
X>0$zE@0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UK{6Rh ;
{ 1Wz -Z
this.sURL = sURL; Stw%OP@?
this.nStartPos = nStart; -!p +^wC
this.nEndPos = nEnd; :P!"'&gCL
nThreadID = id; Qxw?D4/Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SCXH{8SS
} X4- _l$j
7Nw} }
]HpKDb0+
public void run() A7|CG[wZ
{ W.B;Dy,Y
while(nStartPos < nEndPos && !bStop) v2vPfb
{ |oYqkP|
ZmJ!ZKKch
dKKh^D`~
try{ v,=[!=8!
URL url = new URL(sURL); 'dkKBLsx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V>8)1)dF
httpConnection.setRequestProperty("User-Agent","NetFox"); 3G4N0{i
String sProperty = "bytes="+nStartPos+"-"; ZQ&A'(tt4
httpConnection.setRequestProperty("RANGE",sProperty); s8/sH];
Utility.log(sProperty); ,KM-DCwcG
R a> k#pQ
KGVAP
InputStream input = httpConnection.getInputStream(); Ezvm5~<
//logResponseHead(httpConnection); ?PMF]ah
D8w:c6b
mKsTA;
byte[] b = new byte[1024]; $p(,Qz(.8
int nRead; efK3{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H 3e(-
{ x_C#ALq9
nStartPos += fileAccessI.write(b,0,nRead); w<m)T
//if(nThreadID == 1) cz2guUu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qtqTLl@u
} 8 |@WuD
&~%( RO
tt|v opz
Utility.log("Thread " + nThreadID + " is over!"); e)(m0m\
bDownOver = true; shjq4#9
//nPos = fileAccessI.write (b,0,nRead); zW,Nv>Ac5
} @,Re<%\
catch(Exception e){e.printStackTrace ();} R5y+bMZ
} ))pp{X2m
} TAkM-iyH]
g^CAT1}
*=6,}rX"I
//打印回应的头信息 E(0(q#n
public void logResponseHead(HttpURLConnection con) Ap{2*o
{ __FhuP P
for(int i=1;;i++) A7/ R5p
{ af:wg]g
String header=con.getHeaderFieldKey(i); [i8,rOa7
if(header!=null) C*S%aR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5i 6*$#OM_
Utility.log(header+" : "+con.getHeaderField(header)); HjX!a29Wf
else _?5$ST@5
break; 'G.^g}N1
} l&]Wyaz@n
} @IB+@RmL
a^9-9*
Qp~W|zi(
public void splitterStop() ]^>#?yEA3
{ Ik92='Z
bStop = true; l c<&f
} A[,[j?wC
N+<`Er
$WOiXLyCk
} *@M7J
GM5s~,
wbC'SOM
/* Rwy<#9R[x
**FileAccess.java p'`SYEY@Z
*//文件访问(定位，写) \2rCT~x
package NetFox; vFKt=o$ g
import java.io.*; Vd8BQB,Q
}ph;~og}y
nUAs:Q
public class FileAccessI implements Serializable{ *mqoyOa
#-QQ_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -PHVM=:
RandomAccessFile oSavedFile; ?0UzmJV?8
long nPos; nUZ+N)*
V9v80e {n4
zUw9
public FileAccessI() throws IOException y.zS?vv2g
{ 0A~zuK
this("",0); }y-b<J?H
} ]LvpYRU$P
k5>K/;*9
k$V.hG|6M
public FileAccessI(String sName,long nPos) throws IOException &{s`=IeN
{ Min^EAG@
oSavedFile = new RandomAccessFile(sName,"rw"); 5"f')MKUV9
this.nPos = nPos; 9d7$Fz#
oSavedFile.seek(nPos); G/F0)M
} UMg*Yv%
Ksp!xFk
FW)G5^Tf
public synchronized int write(byte[] b,int nStart,int nLen) ZMSP8(V
{ vW\#2[j[
int n = -1; kf3yJP/
try{ =[O;/~J%:
oSavedFile.write(b,nStart,nLen); UB3b
n = nLen; LL~bq(b
} uvo2W!
catch(IOException e) 4v+4qyMyE
{ K-$gTV
e.printStackTrace (); u`l1 zMk
} B!vI^W
HvWnPh1l
yNk9KK)
return n; PvzB, 2":
} *o8DfZ
P:z5/??2S
O87Ptr8
} m6P!#=a:l<
kan?2x
iJg3`1@j
/* 8oI)q4V
**SiteInfoBean.java ,+0>p
*/ ,!"\L~6
package NetFox; $]/a/!d
?]S!-6:
kLKd O0
public class SiteInfoBean { W s!N%%g
/J8'mCuC.
lx<]v^
private String sSiteURL; //Site's URL $ctY#:;pV{
private String sFilePath; //Saved File's Path >$]SYF29
private String sFileName; //Saved File's Name #D"fCVIS
private int nSplitter; //Count of Splited Downloading File ;Ry )^5Q
UE4zmIq
@0`Q
public SiteInfoBean() dU]>
{//nSplitter的缺省值为5 (ilU<Ht
//default value of nSplitter is 5 Z6<vLc
this("","","",5); pIh%5ZU
} Aj06"ep
4'pg>;*.
%2=nS<kC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L3M]06y
{ oI9Jp`
sSiteURL= sURL; bdiyS.a-
sFilePath = sPath; U!sv6=(y@
sFileName = sName; kI974:e42
this.nSplitter = nSpiltter; QE7 r{
{q2H_H
F{cKCqI?
} +%%FT#ce
Qc2_B\K^
;8UHnhk_O
public String getSSiteURL() ~y{(&7sM
{ S5ofe]tS@
return sSiteURL; T!o 4k
} i]Or'L0c
G0Wzx)3]
\[&~.B
public void setSSiteURL(String value) xq',pzN
{ xUE9%qO
sSiteURL = value; yKEE @@}\
} 5gWn{[[e)y
UA3%I8gu_
VIL #q
public String getSFilePath() 2~+Iu+
{ x,"'\=|s*
return sFilePath; EAq/Yw2$
} j r6)K;:.
-\@&^e
z#b31;A@$
public void setSFilePath(String value) :0pxacD"!
{ M?5[#0"&V
sFilePath = value; +<Ot@luE
} $~4ZuV%
93:s[bmx
.H+`]qLkL
public String getSFileName() NS"hdyA
{ 4RsV\Y{FN
return sFileName; m*h d%1D
} XiI@Px?FL
]SpUD
SE{$a3`UzP
public void setSFileName(String value) 6l IFxc
{ mfLS</A
sFileName = value; <1]#E@
} Gs2.}lz
HS| &["
'6u;KIG
public int getNSplitter() %"@KuqV
{ S|Wv1H>
return nSplitter; vBQ|h
} ;7&RmIXKh'
he&*N*of:
a;m-Vu!
public void setNSplitter(int nCount) zzy%dc
{ YVZm^@ZVV
nSplitter = nCount; y!fV+S,
} G_=`&i"4
} RUm1;MWs
!0ySS {/
R1/)Yy
/* erYpeq.
**Utility.java hf>JW[>Xo
*/ QNzI
package NetFox; draY/
I :%(nKBK
P-[6xu+]
public class Utility { "zR+}
>f4H<V-
5YMjvhr?W
public Utility() 8.Wf^j$+{
{ W"YFx*W
Zz=+?L
XJDp%B
} cF3V{b|bU
LHKawEZ
//线程睡眠 #-1 ;
public static void sleep(int nSecond) Af1mTbf=
{ j%Y`2Ra
try{ K+TRt"W8&s
Thread.sleep(nSecond); mu04TPj
} $0V<wsVM
catch(Exception e) z%(m:/N70
{ tM <6c+
e.printStackTrace (); ^tIs57!
} ko*Ir@SDv
} DzYi> E:*
_CDUUr
//日志 F#eZfj~
public static void log(String sMsg) ihBlP\C
{ ir-srVoXy
System.err.println(sMsg); yYwZZa1
} \I1+J9Gl
yNi/JM
=o;8xKj
public static void log(int sMsg) ,1EyT>
{ w`&~m:R
System.err.println(sMsg); i[sHPEml(5
} Hly2{hokq
} C,Q>OkSc
`WGT`A"
py VTA1
/* t J N;WK.6
**TestMethod.java vmm#UjwF3
*/ ~cQ./G4
package NetFox; <R582$( I
C;];4[XR
.(^KA{
public class TestMethod { w4P?2-kB
ER<LP@3k
4qXO8T#~J=
public TestMethod() _>+!&_h
{ ///xx/weblogic60b2_win.exe A-x; ai]
try{ s(jixAf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )0UVT[7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w=H
SiteFileFetch fileFetch = new SiteFileFetch(bean); T1 >xw4uo
fileFetch.start(); ej,j1iB
} f]Z%,'1^
catch(Exception e){e.printStackTrace ();} z)p( l!
zrVw l\&
>?>@&A/
} X)^eaw]Q0
o~<Xc
Q46^i7=
public static void main(String[] args) pW$ZcnU
{ {~q"Y]?
new TestMethod(); 2-=Ov@y2k!
} #0>??]&r
} EZnXS"z
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