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)); 2l9_$evK~
} kns[b [!H
for(int i=0;i<nEndPos.length-1;i++) s:%>H|-
{ NFQ0/iuW
nEndPos = nStartPos[i+1]; `| fF)kI
} FkH4|}1
nEndPos[nEndPos.length-1] = nFileLength; xaPTTa
} aD.A +es
} D`u{U]
Q,>AT$|
mWZVO,t$
//启动子线程 ;I9D>shkc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H=0Y4 T@)T
for(int i=0;i<nStartPos.length;i++) [.2>=3T
{ fSj^/>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f.!cR3XgV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~`y6YIJ3
nStartPos,nEndPos,i); B|!Re4`0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0'gJSrgNI
fileSplitterFetch.start(); )pg?ZM9
} ;(z0r_p<q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uJi|@{V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fNQecDuS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {L#Pdj{
nEndPos = " + nFileLength); h>4\I;Ij
// fileSplitterFetch[nPos.length-1].start(); XWkYhTaY
!O*\|7A(
<|v]9`'
//等待子线程结束 VP[ J#TPU
//int count = 0; zzM 'uo
//是否结束while循环 C@xh$(y
boolean breakWhile = false; 86[TBX5'
TtHqdKL
o_?YYw-:
while(!bStop) 1g *4e
{ J 9z\ qTI
write_nPos(); 0 ~VniF^
Utility.sleep(500); zH.7!jeE
breakWhile = true; 0 j6/H?OT
"/K44(^
zT.qNtU%
for(int i=0;i<nStartPos.length;i++) nM@S`"
{ w9vqFtj
if(!fileSplitterFetch.bDownOver) `Dj-(~x
{ $cc]pJy"}
breakWhile = false; QHK$2xtq|
break; )8yNqnD
} B&cC;Hw
} .QW89e,O3
if(breakWhile) jfk`%CEk=
break; cO' \s
fxjs"rD5
}.x?$C+\"
//count++; a(F%M
//if(count>4) ='a$>JVJ5
// siteStop(); XSXS;Fh)
} Nb-;D)W;B
1I_(!F{Ho
~h -0rE
System.err.println("文件下载结束！"); c'[l%4U8[
} 5MT$n4zKu
catch(Exception e){e.printStackTrace ();} -r[l{ce
} l9\ *G;
"+p_{J/P
2-FL&DE
//获得文件长度 ;:f.a(~c
public long getFileSize() t=5K#SX}
{ 7&E3d P
int nFileLength = -1; Ao(Xz$cQfW
try{ YHl6M&*@
URL url = new URL(siteInfoBean.getSSiteURL()); IF<pT)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); awGI|d
httpConnection.setRequestProperty("User-Agent","NetFox"); (z\@T`6`
tQF,E&Jo8
}PD?x4
int responseCode=httpConnection.getResponseCode(); 8ex{N3
if(responseCode>=400) .cjSgK1
{ LGV"WE
processErrorCode(responseCode); $o0o5 ^Z-
return -2; //-2 represent access is error n)gzHch
} ) m[0,
$)mK]57
]:d`=V\&N
String sHeader; }[k~JXt
V0XQG}
h#a,<B|
for(int i=1;;i++) b|P[\9
{ hvkLcpE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @h$cHZ
//Utility.log(in.readLine()); [td)v,
sHeader=httpConnection.getHeaderFieldKey(i); -)PQ&[
if(sHeader!=null) <`}Oi5nW
{ 1Jjay#
if(sHeader.equals("Content-Length")) E)7vuWOO
{ f%;8]a9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); unKi)v1
break; u,I_p[`E
} 0"#'Z>"
} NJRk##Z
else _SY4Qs`d
break; 1:(qoA:
} R.-2shOE'
} @lRTp
catch(IOException e){e.printStackTrace ();} fYBmW')
catch(Exception e){e.printStackTrace ();} KEEHb2q
>+ulLQqe
f%<kcM2
Utility.log(nFileLength); Cz` !j
&'Pwz
2r4owB?
return nFileLength; J'jwRn
} BIqZg$
ux:czZqy
@z[,w`
//保存下载信息（文件指针位置） mII7p LbQ
private void write_nPos() ..'k+0u^
{ cks53/Z
try{ ~PAF2
output = new DataOutputStream(new FileOutputStream(tmpFile)); $dIu${lu
output.writeInt(nStartPos.length); 'B>fRN
for(int i=0;i<nStartPos.length;i++) AwN7/M~'
{ LlKvi_z
// output.writeLong(nPos); ji9 (!G
output.writeLong(fileSplitterFetch.nStartPos); "^Y)&<J&
output.writeLong(fileSplitterFetch.nEndPos); {}RE;5n\['
} }86&? 0j.
output.close(); GG<{n$h
} ^E{M[;sF3y
catch(IOException e){e.printStackTrace ();} bk^W]<:z`
catch(Exception e){e.printStackTrace ();} LX;w~fRr.
} QhR.8iS
Z\c^CN
IYAvO%~
//读取保存的下载信息（文件指针位置） 4LO4SYW7
private void read_nPos() YW9r'{(D(I
{ )lh48Ag0t;
try{ iYJ:P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <?yf<G'$
int nCount = input.readInt(); dp;;20z
nStartPos = new long[nCount]; F<H[-k*t/
nEndPos = new long[nCount]; Av6=q=D
for(int i=0;i<nStartPos.length;i++) HmlE Cx
{ =A[:]),v
nStartPos = input.readLong(); VAPRI\uM;
nEndPos = input.readLong(); `TwDR6&
} YD>5zV%!D
input.close(); 3h N?l :/b
} b/;!yOF
catch(IOException e){e.printStackTrace ();} :buH\LB*P
catch(Exception e){e.printStackTrace ();} 17kh6(X
} KT'Ebb]
K=lm9K
PY.4J4nn|
private void processErrorCode(int nErrorCode) IY_u|7d
{ ^K[WFiN}
System.err.println("Error Code : " + nErrorCode); k+qxx5{
} F9h'.{@d
}#'I,?_k
^jY/w>UdH
//停止文件下载 FVY$A=G
public void siteStop() 6WI-ZEVp&
{ pAK7V;sJ
bStop = true; gbf2ty
for(int i=0;i<nStartPos.length;i++) <7
fileSplitterFetch.splitterStop(); j<,Ho4v}_
B"; >zF
<;eXbO>Q
} "&9L
} F"I{_yleq'
//负责部分文件的抓取 7 k:w3M
**FileSplitterFetch.java \Dn47V{7-
*/ M8Tj;ATr
package NetFox; (g(.gN]
l rRRRR
XHN*'@ 77;
import java.io.*; I| Vyv
import java.net.*; '>"riEk
cpY'::5.%
8VWkUsOoI
public class FileSplitterFetch extends Thread { gC/~@Z8W]
<t~RGn3
n7EG%q6m+
String sURL; //File URL NI<;Lm
long nStartPos; //File Snippet Start Position 5>S=f{ghFw
long nEndPos; //File Snippet End Position @Yzdq\FI
int nThreadID; //Thread's ID :NCY6? [Dz
boolean bDownOver = false; //Downing is over r:.ydr@
boolean bStop = false; //Stop identical k_,wa]ws$
FileAccessI fileAccessI = null; //File Access interface T> < Vw
&7 0o4~Fr
dGc<{sQzB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n "J+?~9
{ %@q/OVnM
this.sURL = sURL; ^i;y2c
this.nStartPos = nStart; O>vbAIu
this.nEndPos = nEnd; {p90
nThreadID = id; $E >)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =cP7"\
} HxE`"/~.7k
)8,)&F
p?Rq
public void run() dv7IHUFf
{ fR^aFT
while(nStartPos < nEndPos && !bStop) q8=hUD%5C
{ ' K\ $B_
Fv!KLw@
@lO(QpdG
try{ _T^+BUw
URL url = new URL(sURL); VV%Q "0\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yG/_k!{9
httpConnection.setRequestProperty("User-Agent","NetFox"); ;,&$ob*/
String sProperty = "bytes="+nStartPos+"-"; /4xp?Lo:
httpConnection.setRequestProperty("RANGE",sProperty); KD(}-zUs
Utility.log(sProperty); S-Z s
0*4h}t9j
_Pe,84Ro
InputStream input = httpConnection.getInputStream(); ]+)cXJ}6#
//logResponseHead(httpConnection); G&DL)ePu]m
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PKK18E}{%^
byte[] b = new byte[1024]; ^6?)EM#
int nRead; nyRQ/.3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wU $j/~L
{ kCVO!@yZz
nStartPos += fileAccessI.write(b,0,nRead); N5%Cwl6i
//if(nThreadID == 1) <q<kqy5s-R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,bU8S\8
} h+"UK=
c&]nAn(
&}."sGK
Utility.log("Thread " + nThreadID + " is over!"); EZw<)Q
bDownOver = true; 7wA.:$
//nPos = fileAccessI.write (b,0,nRead); e^ ZxU/e
} %]iE(!>3oy
catch(Exception e){e.printStackTrace ();} ,JVWn>s
} AzlZe\V?)~
} g UAx8=h
%.nZ@';.
P)9$}9i
//打印回应的头信息 mu/GOEZ5
public void logResponseHead(HttpURLConnection con) ?V9Da;cj
{ *?<ygzX
for(int i=1;;i++) (7k}ysc
{ Q"VS;uh.v
String header=con.getHeaderFieldKey(i); ))xyaYIZkk
if(header!=null) 6|HxBC#4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #l<un<
Utility.log(header+" : "+con.getHeaderField(header)); mR|;}u;d
else +/|;<K5_LI
break; %fH&UFby
} 9% wVE]
} NKX62 ZC
*l9Wj$vja
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public void splitterStop() wx]r{
{ [.[|rnil
bStop = true; X 8#Uk}/
} f?P>P23
\]7i-[
3Gyw^_{J
} KbicP<
,%!E-gr
,fR/C
/* {<J(*K*\Jo
**FileAccess.java UU;U,q
*//文件访问(定位，写) ab/^z0GT
package NetFox; t_\;G~O9-M
import java.io.*; *41 2)zEy
D$&LCW#x
*ke9/hO1i
public class FileAccessI implements Serializable{ >x0)
^W)h=49PN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "u=U@1 ^
RandomAccessFile oSavedFile; b>_eD-
long nPos; -z6{!
= 3("gScUj
3{"MN=
public FileAccessI() throws IOException K H&o`U(}
{ R'e>YDC
this("",0); <{"Jy)Uf
} +`_Km5=
C#3K.0a
R|OY5@
public FileAccessI(String sName,long nPos) throws IOException :.J]s<J(F
{ "'zVwU
oSavedFile = new RandomAccessFile(sName,"rw"); N |nZf5{
this.nPos = nPos; u ^}R]:n
oSavedFile.seek(nPos); +ia N[F$
} {%PgR){qR
{EL J!o[
|tua*zEsS
public synchronized int write(byte[] b,int nStart,int nLen) 2z+-vT%
{ \7elqX`.yY
int n = -1; \[MQJX,dn
try{ h^aUVuL/
oSavedFile.write(b,nStart,nLen); l+n0=^ Z
n = nLen; /tqQAvj
} p*l]I*x'<
catch(IOException e) Ph Ep3o&"
{ p+7ZGB
e.printStackTrace (); PYPDK*Ie
} wz1fl#WU
g*a|QBj%
Z7:TPY$b
return n; B(/)mB
} R.rxpJ+kU
x=jS=3$8
@Z{!T)#}j
} %*Aq%,.={
XeRbn
(Ymj
/* ^}\!Sn
**SiteInfoBean.java 1,pg7L8H
*/ WAWy3i
package NetFox; W2-1oS~ma
d|Q_Z@;JF
klON6<w
public class SiteInfoBean { @5Zg![G
n k@e#
sn=_-uoU
private String sSiteURL; //Site's URL _A5.
private String sFilePath; //Saved File's Path k6|wiSyu
private String sFileName; //Saved File's Name =U)e_q
private int nSplitter; //Count of Splited Downloading File 5$;#=WAY
NJ];Ck
8/oO}SLF
public SiteInfoBean() l:?w{'i$
{//nSplitter的缺省值为5 gxf{/EjH
//default value of nSplitter is 5 %V2A}78
this("","","",5); hErO.ad1o
} t.YY?5l
E%tGwbi7
(I7s[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p#DJow
{ ,4`=gKn
sSiteURL= sURL; IJz=SV
sFilePath = sPath; }_[Bp
sFileName = sName; XA4miQn&
this.nSplitter = nSpiltter; CUG3C
-w#*~Q{'*
8n`O{8:fi
} ;(1Xb
[<H'JsJl
!caY
public String getSSiteURL() )~CnDk}^R
{ jXCSD@?]K
return sSiteURL; {=)g?!zC
} :,]*~Nl
D<SLv,Y
CQGq}.Jt!
public void setSSiteURL(String value) Q`* v|Lp
{ *W&}}iL
sSiteURL = value; +*AdSzX
} wx2EMr
/CW 0N@
hI Q 2s
public String getSFilePath() THcK,`lX@
{ ?^l{t4
return sFilePath; %D9,Femt
} +T|M U
KbP( ;
"jFRGgd79
public void setSFilePath(String value) aUVJ\;V
{ `$hna{e^n
sFilePath = value; d=J$H<
} S(nZ]QEG
X_tc\}I]
[h;&r"1
public String getSFileName() m.|__L
{ w4UaWT1J
return sFileName; HC[)):S*
} yCt,-mz!z
dYP-QUM$7
p#fd+
public void setSFileName(String value) e_iXR#bZc
{ ^P| K2at
sFileName = value; p(J,fus
} h0v4!`PQ-
&y~EEh|
N=hhuKt]
public int getNSplitter() H/Wo~$
{ Ny oRp
return nSplitter; ;uK">L[u'
} Q \E[py
}%m:^*@$9
:% o32
public void setNSplitter(int nCount) N9s ,..
{ W\W|v?r
nSplitter = nCount; `VB]4i}u
} LBs:O*;
} ejID5NqG
GNIZHyT(O
,m^@S
/* Xgs 31#K
**Utility.java K}(0H[P
*/ <l,Kg 'v
package NetFox; *;]j#0
k&kx%skz
5m e|dvk
public class Utility { 9*"Ae0ok1
V6.w=6:`X
MK*WStY
public Utility() 6)QJms
{ 5NT?A,r"
p` '8M
n qR8uL>
} 5V{ B,T
8,(FJ7OCT,
//线程睡眠 fCq
public static void sleep(int nSecond) D02_ Jrg
{ ee9nfvG-
try{ $d[xSwang
Thread.sleep(nSecond); +}u{{
} Gl+Ql?|
catch(Exception e) ?3vOc/2@
{ iHp@R-g
e.printStackTrace (); ATdK)gG
} lM<SoC;[
} 0d%p<c
tk"+PTGJT
//日志 4IW7^Pq`P
public static void log(String sMsg) }E}b/ulg1
{ pu"`*NL
System.err.println(sMsg); 3O W)%
} [J6*Q9B<V&
y].vll8R
AhjUFz
public static void log(int sMsg) r-ldqj
{ H,F/u&O
System.err.println(sMsg); 0%9Nf!j
} iyRB}[y
} .Y?/J,Ch
6@2 S*\&
.7!n%Ks
/* 7Z(F-B +j
**TestMethod.java 1 >nl ]yO
*/ )AX0x1I|E
package NetFox; Pd,+= ML
eTV%+
Mk*&CNo3
public class TestMethod { YRkp(}*!\
$SP*hkU
jf_0IE
public TestMethod() e2SU)Tr%b
{ ///xx/weblogic60b2_win.exe |+^-b}0
try{ fCA/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *=-o0c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :[#~,TW
SiteFileFetch fileFetch = new SiteFileFetch(bean); OYWW<N+R2
fileFetch.start(); | Q Y_ci
} /<HEcB
catch(Exception e){e.printStackTrace ();} NbD"O8dL~E
X>n\@rTo
rb/m;8v>
} suh@
,C#Mf@b
N@M(Iw
public static void main(String[] args) hLVS}HE2
{ Wp0e?bK_
new TestMethod(); @$5GxIw<l
} > n~l\ fC
} I[~EQ{Iz
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