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)); kHO2&"6
} +@'{
for(int i=0;i<nEndPos.length-1;i++) g1je':
{ t8"*jt
nEndPos = nStartPos[i+1]; )YDuq(g&
} RG'Ft]l92N
nEndPos[nEndPos.length-1] = nFileLength; %TY;}V59b
} fQ\nK H~
} !n=?H1@
B@:c8}2.
+0w~Skd,
//启动子线程 a?zn>tx
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >q'xW=Y j\
for(int i=0;i<nStartPos.length;i++) `]Uu`b
{ 69 PTo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'f#i@$|]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +<G |Ru-
nStartPos,nEndPos,i); p19[qy~.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @>wD`<U|
fileSplitterFetch.start(); j|`6[93MG
} sHqs)@D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fpjy[$8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *^BW[C/CTR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6m.ChlO/
nEndPos = " + nFileLength); "[PxLq5
// fileSplitterFetch[nPos.length-1].start(); Zu4|1W
L|y4u;-Q
|WopsV %
//等待子线程结束 pjC2jlwm*
//int count = 0; b7 pD#v
//是否结束while循环 1]yOC)u"i
boolean breakWhile = false; >-2eZ(n)"
[79 eq=
(,5oqU9s@
while(!bStop) Mp*S+Plp
{ Wc}opp
write_nPos(); DFgr,~
Utility.sleep(500); uHBEpqC%
breakWhile = true; kOe%w-_
+d[A'&"
*]ROUk@K=
for(int i=0;i<nStartPos.length;i++) bv.DW,l%'
{ QT1(= wK3
if(!fileSplitterFetch.bDownOver) ugtzF
{ }Yi)r*LI3
breakWhile = false; dmq<vVxC
break; tSST.o3
} C~do*rnM^
} p!+7F\
if(breakWhile) L<kIzB !
break; e&Z\hZBb
T;cyU9
Wq bfZx
//count++; g/)$-Z)Nu
//if(count>4) 59?@55
// siteStop(); -#=y
} .k{omr&Dy5
|G2hm8 Y
\JJ>y
System.err.println("文件下载结束！"); "2>I?
} 0jS"PH?[
catch(Exception e){e.printStackTrace ();} i\P?Y(-{
} - nWs@\
:NB,Dz+i
8+m[ %5lu
//获得文件长度 Qfhhceb6#J
public long getFileSize() U=?hT&w\S
{ @WppiZ$
int nFileLength = -1; R&z)
try{ qz|`\^
URL url = new URL(siteInfoBean.getSSiteURL()); )+^1QL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); omxBd#;F$
httpConnection.setRequestProperty("User-Agent","NetFox"); T&?0hSYt
z|Z<S+=f
#n=b*.
int responseCode=httpConnection.getResponseCode(); kzA%.bP|
if(responseCode>=400) U'pm5Mc\q
{ Zk#^H*jgx
processErrorCode(responseCode); tEz6B}
return -2; //-2 represent access is error P;&rh U^[
} <Tq&Va_w
0nkon3H
-rU~
String sHeader; 2gn*B$a
ryz [A:^G
#z|\AmZ\
for(int i=1;;i++) ~[@Gj{6p0
{ ^y@RfM=A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~<M/<%o2*
//Utility.log(in.readLine()); sGNVZx
sHeader=httpConnection.getHeaderFieldKey(i); dg%Orvuz
if(sHeader!=null) us&!%`
{ 6E9y[ %+
if(sHeader.equals("Content-Length")) )P6n,\
{ NLe+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]J^9iDTTA
break; .s4hFB^n
} U] 2fV|Hn
} Jjb(lW
else 9aLS%-x!+
break; &G5=?ub
} jB8n\8Bs
} `={s*^Ta
catch(IOException e){e.printStackTrace ();} zNE"5
catch(Exception e){e.printStackTrace ();} %G%##wv:
*7"R[!9
> ,L'A;c}
Utility.log(nFileLength); Oeo:V"
H].G%,2'
Onr#p4UT
return nFileLength; Da)rzr|}>3
} Zk+J=Cwq}
NO4V{}?a
xl%!7?G|$>
//保存下载信息（文件指针位置） s52c`+
private void write_nPos() x4SI TY
{ lO/<xSjNd
try{ By=/DVm)=
output = new DataOutputStream(new FileOutputStream(tmpFile)); qyP|`Pm4
output.writeInt(nStartPos.length); zy(i]6
for(int i=0;i<nStartPos.length;i++) P)fv:a
{ b\zRwp
// output.writeLong(nPos); >uN`q1?l'
output.writeLong(fileSplitterFetch.nStartPos); &"dT/5}6
output.writeLong(fileSplitterFetch.nEndPos); KKm0@Y
} CroI,=a&,
output.close(); W)"PYC4
} ^(ks^<}
catch(IOException e){e.printStackTrace ();} VjU;[
catch(Exception e){e.printStackTrace ();} =RR225
} @l9qH1
J@ x%TA
_C9*M6IU
//读取保存的下载信息（文件指针位置） KlgPDV9mg
private void read_nPos() e&dE>m
{ QN[-XQ>Xt
try{ )hH9VGZq(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GyV3]Qqj
int nCount = input.readInt(); !F0MLvdX7^
nStartPos = new long[nCount]; g-=)RIwm
nEndPos = new long[nCount]; tt=?*n
for(int i=0;i<nStartPos.length;i++) H'myd=*h~8
{ ?iH`-SY
nStartPos = input.readLong(); Ti/t\'6
nEndPos = input.readLong(); r3o_mO?X
} L&1VPli
input.close(); ; Xy\7tx
} uLYz!E+E
catch(IOException e){e.printStackTrace ();} e{edI{g
catch(Exception e){e.printStackTrace ();} !1f8~"Z
} z`-?5-a]I
LOyL:~$
xq:.|{HUk
private void processErrorCode(int nErrorCode) x^aqnKoJ%\
{ uX{n#i,~L
System.err.println("Error Code : " + nErrorCode); N> RabD
} MnvFmYgxA
ag^L' h$
!j8h$+:K
//停止文件下载 37)Dx
public void siteStop() qkC+9Sk
{ w]n20&
bStop = true; :.!]+#Me
for(int i=0;i<nStartPos.length;i++) 96aA2s1
fileSplitterFetch.splitterStop(); :>to?~Z1
dzZ74FE!t
BM*9d%m^
} i<|5~tm
} @psyO]D=j%
//负责部分文件的抓取 }7CMXw [
**FileSplitterFetch.java .op: 2y9]
*/ 0bxB@(NO
package NetFox; 3X$)cZQ
Y:C7S~
OKfJ
import java.io.*; 8~?3: IZ
import java.net.*; !oeu
4 vwa/?
>{i/LC^S
public class FileSplitterFetch extends Thread { xwa5dtcng
$x5P5^Y
n(.y_NEgV!
String sURL; //File URL ]gYnw;W$
long nStartPos; //File Snippet Start Position 2Yt#%bj7^
long nEndPos; //File Snippet End Position U@+ @Mc
int nThreadID; //Thread's ID uR{HCZ-
boolean bDownOver = false; //Downing is over u2 a U0k:
boolean bStop = false; //Stop identical FR9<$
FileAccessI fileAccessI = null; //File Access interface X l#P@60
mxtLcG4G
Z%~j)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LRBcW;.Su
{ }}XYV eI
this.sURL = sURL; edhNQWn
this.nStartPos = nStart; *,hS-
this.nEndPos = nEnd; t4pc2b
nThreadID = id; t3K7W2bz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D.o|pTZ
} }fnp}L
kf+]bV
MZf$8R
public void run() XnrOC|P$
{ D/jB.
while(nStartPos < nEndPos && !bStop) G?!b00H
{ `HvU_ja;
9ctvy?53H
fk4s19;?
try{ IbC(/i#%`
URL url = new URL(sURL); egboLqn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IlsXj`!e
httpConnection.setRequestProperty("User-Agent","NetFox"); O{a<f7 W
String sProperty = "bytes="+nStartPos+"-"; pfgFHNH:
httpConnection.setRequestProperty("RANGE",sProperty); n'=-bj`
Utility.log(sProperty); ,wE]:|`qJ
8<M'~G%CEq
mh]'/C_*<w
InputStream input = httpConnection.getInputStream(); ?-0k3
//logResponseHead(httpConnection); %)T>Wn%b]v
;4tVFqR
+[*VU2f t
byte[] b = new byte[1024]; }\}pSqW
int nRead; `E>HpRcxD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L<!}!v5ja
{ :#58m0YLA:
nStartPos += fileAccessI.write(b,0,nRead); V{;!vt~
//if(nThreadID == 1) Xu`c_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F+Rtoq|
} 8*3o9$Pj
pDb5t>
'gk.J
Utility.log("Thread " + nThreadID + " is over!"); \bqIe}3V7
bDownOver = true; PHl{pE*
//nPos = fileAccessI.write (b,0,nRead); %"PG/avo
} s42M[BW]
catch(Exception e){e.printStackTrace ();} .GUm3b
} >k,|N4(
} J]/TxUE
%`%oupqm+
!"/]<OQ
//打印回应的头信息 =3OK3|
public void logResponseHead(HttpURLConnection con) $Z6g/bD`E
{ mZ 39 s
for(int i=1;;i++) %eWzr
{ !!Z#'Wq
String header=con.getHeaderFieldKey(i); 4s nL((
if(header!=null) =LV7K8FSd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tAFKq>\
Utility.log(header+" : "+con.getHeaderField(header)); 3Yf&F([t
else w2!G"oD
break; n4Nb,)M
} SLp &_S@4
} P'f =r%
m7wD#?lm
CY#|VE M
public void splitterStop() /ylO["<Q
{ 1ael{b!
bStop = true; rF:C({y
} }&D~P>1
h\\fb[``
qd#?8
} qp_lMz
.gTla
Hs/ aU_
/* lo*OmAF
**FileAccess.java \7PPFKS
*//文件访问(定位，写) Q\Dx/?g!vx
package NetFox; r!SMF]?SJ
import java.io.*; ^Gt&c_gH
u~n*P``{
)9F-h8 &"
public class FileAccessI implements Serializable{ f =@'F=
Ix@rn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >QO^h<.>
RandomAccessFile oSavedFile; g^|}e?
long nPos; X{4jyi-<
T<(1)N1H`
#\s*>Z
public FileAccessI() throws IOException .[&0FHnJ5
{ ap=m5h27
this("",0); ~_opU(;f
} aX`"V/
+v.uP[H
{<&i4;
public FileAccessI(String sName,long nPos) throws IOException @_s`@,=
{ Ie{98
oSavedFile = new RandomAccessFile(sName,"rw"); Cbu/7z
this.nPos = nPos; ]&6# {I-
oSavedFile.seek(nPos); HS>(y2}'
} !/]F.0
8*7t1$
.4on7<-a
public synchronized int write(byte[] b,int nStart,int nLen) & $E[l'
{ uQh dg4
int n = -1; X[/>{rK
try{ ]v^/c~"${
oSavedFile.write(b,nStart,nLen); fy+fJ )4sj
n = nLen; mdjPKrF<
} &*2\1;1tB
catch(IOException e) {gh41G;n
{ 2gM=vaiH=
e.printStackTrace (); kFKc9}7W
} Mo?eVtZ
s~e<Pr?yu
|dIP &9
return n; Qn=3b:S-
} e_'/4 n
AGaM &x=
BS3Aczwk
} ,=sbK?&
Ku;|Dz/=o
\f| Hk*@
/* DV+M;rs
**SiteInfoBean.java 9R_2>BDn
*/ 9/A$3#wF
package NetFox; _)|_KQQu
F6>K FU8
:5)Dn87
public class SiteInfoBean { vHR-mQUs
TdGda'C
>tF3|:\
private String sSiteURL; //Site's URL 'Cv,:Q
private String sFilePath; //Saved File's Path ]0N'Wtbn
private String sFileName; //Saved File's Name TljN!nv]
private int nSplitter; //Count of Splited Downloading File *u LOoq
k(hYNmmo j
d4ANh+}X"_
public SiteInfoBean() ,TeJx+z^
{//nSplitter的缺省值为5 )Ve-)rZ
//default value of nSplitter is 5 #,dNhUV#
this("","","",5); ?%RAX CK
} G!]%xFwYa
,RmXZnWY
h>ZNPP8N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Oi#4|*b{W
{ 5)712b(&
sSiteURL= sURL; rP4v_?Zg+
sFilePath = sPath; vW6 a=j8
sFileName = sName; Xge]3Ub
this.nSplitter = nSpiltter; =BD}+(3
%=p:\+`VI
^gw htnI
} [6 d~q]KH
^RL#(O
nc<wDE6
public String getSSiteURL() 5x$/.U
{ ~ZrSoVP=
return sSiteURL; LV4\zd6
} /#mq*kNIM6
.II*wKk
{ 'A`ram
public void setSSiteURL(String value) x"g-okLN
{ BdWRm=
sSiteURL = value; sk'<K5~
} vjo@aY.x
WP(+jL^-
'Cki"4%<
public String getSFilePath() zzlqj){F
{ JFOto,6L:
return sFilePath; :TU|;(p
} ku2gFO
s|40v@M
|W't-}yf
public void setSFilePath(String value) '5^$v{
{ g/*x;d=
sFilePath = value; m(2(Caz{
} NO$n-<ag
PK&3nXF%4
C\-Abqc
public String getSFileName() By3y.}'Ub9
{ X?6E0/r&9
return sFileName; N=2BrKb)o
} rw CFt6;v
rbC4/9G\
!T+jb\O_
public void setSFileName(String value) '(ZJsw
{ ]V*ku%L0
sFileName = value; 6snDv4
} 4}i2j
SW94(4qo
LwPZRE#
public int getNSplitter() fj 14'T
{ s,5SWdb\v
return nSplitter; VV_Zrje
} rTJ='<hIy
wEQ7=Gyx
M<Gr~RKmAn
public void setNSplitter(int nCount) JA=9EnTU
{ C-wwQbdG/
nSplitter = nCount; l7{]jKJue
} f82$_1s^
} {J aulg
/5x~3~
}kNbqwVP
/* It5U=PU
**Utility.java M lv
*/ KOQiX?'
package NetFox; }"$2F0
A~2U9f+\
t>f61<27eB
public class Utility { FWi c/7
[H~Yg2O
gKp5*
public Utility() S%NS7$`a
{ jruXl>T!U
E$u9Jbe
';'TCb{f*
} K;n2mXYGM
D]n"`< Ho
//线程睡眠 _oV;Y`_
public static void sleep(int nSecond) z XI [f
{ >"OwdAvX
try{ i146@<\G{P
Thread.sleep(nSecond); L9lNAiOH
} |*G$ilu
catch(Exception e) \tpJ
{ X2RM*y|
e.printStackTrace (); /0S2Omh
} k`j>lhH
} J 8!D."'Q0
zRO-oOJ
//日志 \(4"kY_=
public static void log(String sMsg) Dw%V.J/&o
{ 2 }9of[
System.err.println(sMsg); Z.4 vKO[<
} a&sVcsX
"wPA;4VQ
@ij8AGE:
public static void log(int sMsg) /.knZ_aJ!
{ 6%jv|\>
System.err.println(sMsg); JYAtQTOR
} `6R.*hq
} ;)6LX-
T(GEFntY
%=ZN2)7{
/* b]-~{' +
**TestMethod.java 5s5GBJ?
*/ 5l(8{,NDt
package NetFox; X0QY:?
}3b3^f
b I%Sq+"}
public class TestMethod { pBZf=!+E
G{ |0}
*A^j>lV
public TestMethod() ^|b]E
{ ///xx/weblogic60b2_win.exe UQ7E7yY#
try{ z: ;ZPSn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &Zzd6[G+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +vDEDOS1
SiteFileFetch fileFetch = new SiteFileFetch(bean); +#B4Z'nT
fileFetch.start(); 1X ?9Ji)h
} m'!smSx8
catch(Exception e){e.printStackTrace ();} *mvDh9v
;0Vyim)S]
rXIFCt8J
} k=nN#SMn
*y}<7R
$] gwaJ:
public static void main(String[] args) p)x*uqSd
{ H'2J!/V
new TestMethod(); ,qj1"e
} n#US4&uT4A
} 3 L:s5
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