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)); a4!6K
} FC8= ru
for(int i=0;i<nEndPos.length-1;i++) _Q\u-VN*hv
{ !un_JZD
nEndPos = nStartPos[i+1]; umiD2BRZ
} P$;_YLr
nEndPos[nEndPos.length-1] = nFileLength; 04z2gAo
} !r0 z3^*N
} F8Z6Ss|v3
TUd=qnu
W}oAgUd
//启动子线程 VoUAFEcs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C?b_E
for(int i=0;i<nStartPos.length;i++) g\,HiKBXd
{ \3z^/F~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ( e(<4-&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }*0*8~Q'5
nStartPos,nEndPos,i); Yr+ghl/ V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +wr 5&
fileSplitterFetch.start(); 9DmQ
} RFm9dHI27
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D#&N?<}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gLv";"4S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .J|"bs9
nEndPos = " + nFileLength); ^`!EpO>k9
// fileSplitterFetch[nPos.length-1].start(); o"A%dC_
YPav5<{a
P}Ule|&LK
//等待子线程结束 5 %aT
//int count = 0; $;+`sVG
//是否结束while循环 o//PlG~
boolean breakWhile = false; T k>N4yq
$yg}HS7HC
!7[Rhk7bW
while(!bStop) dCMWv~>
{ l.i&.;f
write_nPos(); C{):jH,Rf
Utility.sleep(500); y#;@~S1W
breakWhile = true; V?Zvu9b&
0IjQqI
"Mmvf'N
for(int i=0;i<nStartPos.length;i++) /!0{9F<
{ jCbxI^3A
if(!fileSplitterFetch.bDownOver) :j,e0#+sA
{ t%<d}QuHW
breakWhile = false; zc-.W2"Hu
break; J;BG/VI1
} e c`3Qw
} :ITz\m
if(breakWhile) <)(STo
break; xlaBOKa%
wXsA-H/`
QFf lx
//count++; dPRGL hWF
//if(count>4) e[8p/hId
// siteStop(); 7uRXu>h
} a|@^N
. RNQlh3
'rdg
System.err.println("文件下载结束！"); Nl1v*9_x
} Jk7[}Jc$
catch(Exception e){e.printStackTrace ();} vg1p{^N!
} E8Wgm 8
)f0t"lk
!Hr +|HKQ?
//获得文件长度 v 1O* Q
public long getFileSize() T=2 91)@
{ x3my8'h@
int nFileLength = -1; U;4:F{3m
try{ 8ESBui3;
URL url = new URL(siteInfoBean.getSSiteURL()); ,Tyh._sa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `7|v
httpConnection.setRequestProperty("User-Agent","NetFox"); <H~ (iQ
l+Tw#2s$
`riK[@
int responseCode=httpConnection.getResponseCode(); |L7 `7!Z
if(responseCode>=400) TlZ|E '_C
{ S-:l 60.
processErrorCode(responseCode); 3&-BO%i
return -2; //-2 represent access is error kf$0}T`
} t{K1ht$[:
*/RtN`dh
Jh[fFg]
String sHeader; %c(':vI#
y_8 8I:O
X4Eq/q"
for(int i=1;;i++) A=|&N%lP'
{ Wel-a< e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *A O/$K@Ma
//Utility.log(in.readLine()); <$HP"f+<S5
sHeader=httpConnection.getHeaderFieldKey(i); ?E2/ CM
if(sHeader!=null) U)+Yh
{ 5>JrTO5
if(sHeader.equals("Content-Length")) $}7/mS@c
{ #IyxH$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m4|9p{E
break; Jpws1~
} {cKKTDN
} KyNv)=x4c
else +=^10D
break; ]Z@-r
} 7\K=8G
} >ZuWsA0q
catch(IOException e){e.printStackTrace ();} {(AYs*5
catch(Exception e){e.printStackTrace ();} uG2Hzav
J(VJMS;_
c:4M|t=
Utility.log(nFileLength); *K'(t
`$7j:<c=
O!kBp(?]
return nFileLength; vWcU+GBZI
} TB4|dj-%
R-"A*/A 2
@%fNB,H`
//保存下载信息（文件指针位置） Y dmYE$
private void write_nPos() <MI>>$seiJ
{ \L(~50{(
try{ pog*}@OS
output = new DataOutputStream(new FileOutputStream(tmpFile)); KE`}P<K&
output.writeInt(nStartPos.length); ]4yWcnf
for(int i=0;i<nStartPos.length;i++) B{lBUv(B
{ V,fSn:8%M
// output.writeLong(nPos); egxh
output.writeLong(fileSplitterFetch.nStartPos); sME3s-
output.writeLong(fileSplitterFetch.nEndPos); U`D/~KJ{Y
} q<yp6Q3^
output.close(); $uF}GP_)
} >Q#_<IcI
catch(IOException e){e.printStackTrace ();} lzN\~5a}
catch(Exception e){e.printStackTrace ();} AF>J8V
} fn(KmuNA
|[;9$Vn
+HQX]t:Y
//读取保存的下载信息（文件指针位置） Ua)ARi %
private void read_nPos() B)O{+avu
{ (hS j4Cp
try{ Tf)qd\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K 38e,O
int nCount = input.readInt(); )'KkO$^&
nStartPos = new long[nCount]; iVLfAN @
nEndPos = new long[nCount]; r'#5ncB
for(int i=0;i<nStartPos.length;i++) r1yz ?Y_P
{ M3c-/7
nStartPos = input.readLong(); h.E8G^}@
nEndPos = input.readLong(); /\V-1 7-
} (PE x<r1
input.close(); 8hZ+[E}
} @-Tt<pl'L
catch(IOException e){e.printStackTrace ();} 8<z+hWX=4
catch(Exception e){e.printStackTrace ();} 1~Zmc1]
} 'kf]l=i[n
E4GtJ`{X
}9<pLk
private void processErrorCode(int nErrorCode) N?TXPY
{ EaaQC]/OX5
System.err.println("Error Code : " + nErrorCode); 85+'9#~!
} _SC{nZ[
)HQ':ZE$
> L_kSC?
//停止文件下载 sa$CCQ
public void siteStop() lk]q\yO_%
{ eW,{E)x:
bStop = true; HjAhz
for(int i=0;i<nStartPos.length;i++) 4t]ccqX*{
fileSplitterFetch.splitterStop(); 'hN_H}U
mN?y\GB
N"1o> !
} d(9ZopJrQ
} y_boJ
//负责部分文件的抓取 L_3Ao'SA
**FileSplitterFetch.java $L7Z_JD5
*/ k!l\|~
package NetFox; tBC`(7E}
v1h\ 6r'
\H^DiF%f9
import java.io.*; r==d^
import java.net.*; IcRA[ g
d$qivct
Vea2 oQq
public class FileSplitterFetch extends Thread { =jXBF.
g<pr(7jO
uF,F<%d
String sURL; //File URL /9T.]H~
long nStartPos; //File Snippet Start Position _)-t#Ve
long nEndPos; //File Snippet End Position 3m%oXT
int nThreadID; //Thread's ID C+o1.#]JM
boolean bDownOver = false; //Downing is over n-zAkKM
boolean bStop = false; //Stop identical T%74JRQ
FileAccessI fileAccessI = null; //File Access interface ~(i#A>
>-U'mkIH
3L}eFg,d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException '. 5&Z
{ +~xY}
this.sURL = sURL; s^f7w
this.nStartPos = nStart; K#Ia19au5
this.nEndPos = nEnd; yp}J+/PX}
nThreadID = id; QS7<7+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wW &q)WOi
} hOFC8g
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)Fk*'6
public void run() 9o%k [n
{ e1cqzhI=nA
while(nStartPos < nEndPos && !bStop) HiAj3
{ tVfZ~qJ
) uM*`%
6Qtyv
try{ jW]Q-
URL url = new URL(sURL); BoJpf8e'-e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Td,2.YMQ
httpConnection.setRequestProperty("User-Agent","NetFox"); zF: :?L~
String sProperty = "bytes="+nStartPos+"-"; M%&1j >d
httpConnection.setRequestProperty("RANGE",sProperty); +;r1AR1)x
Utility.log(sProperty); U]/iPG&_
"x1?T+j4
mIW8K ):
InputStream input = httpConnection.getInputStream(); 75v7w
//logResponseHead(httpConnection); N+lhztYQ?
eX`wQoV%
}2xgm9j<
byte[] b = new byte[1024]; e={ ?d6
int nRead; BD.&K_AW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) arK(dg~S
{ 3Z0ez?p+5
nStartPos += fileAccessI.write(b,0,nRead); 4,g_$)
//if(nThreadID == 1) \ -n&z;`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z }3`9
} t@X{qm:%Z
8'WoG]E_
r+=%Ag
Utility.log("Thread " + nThreadID + " is over!"); oYx4+xH/
bDownOver = true; Ml,~@} p
//nPos = fileAccessI.write (b,0,nRead); --OAsbr
} ^8.s"4{
catch(Exception e){e.printStackTrace ();} h`i*~${yg
} n4XEyCrD
} u@]rR&h`
b=@H5XTZyK
w{8O$4 w
//打印回应的头信息 g)dKXsy(F
public void logResponseHead(HttpURLConnection con) Xsk/U++
{ `.i #3P
for(int i=1;;i++) >o:y.2yCe
{ / jLb{Ky
String header=con.getHeaderFieldKey(i); ]hMs:$}
if(header!=null) g3|k-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B_DyH C\<
Utility.log(header+" : "+con.getHeaderField(header)); h ?_@nQ!
else xiv8q/
break; Vp$<@Y
} @[LM8 @:
} nt:ZO,C:R
:(Ak:
HXm&`
public void splitterStop() 3>>Ca;>$
{ KzZfpdI92
bStop = true; ilRPV'S^
} /'4]"%i%3
-e\OF3Td
]FNe&o1zX
} $bU.6
bV$g]->4e
xLdkeuL[%
/* _TwEym.V
**FileAccess.java /Qu<>#[?
*//文件访问(定位，写) L,yq'>*5s
package NetFox; 5{gv\S1
import java.io.*; -G[TlH06
lT?Vt`==~M
wZ5k|5KtW
public class FileAccessI implements Serializable{ ! FVD_8
RD6>\9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /H?) qk
RandomAccessFile oSavedFile; 4`Cgz#v {
long nPos; zr ~4@JTS
'/s/o]'sUd
}0Q T5
public FileAccessI() throws IOException |J"\~%8
{ *5u3d`bW
this("",0); wwNkJ+
} c!kzwc(
%x./>-[t
+TW,!.NBG
public FileAccessI(String sName,long nPos) throws IOException fh*7VuAc
{ hzk4SOT(
oSavedFile = new RandomAccessFile(sName,"rw"); xyP0haE
this.nPos = nPos; },=ORIB B:
oSavedFile.seek(nPos); N(e>]ui
} a51}~V1
)j QrD`
iu9+1+-
public synchronized int write(byte[] b,int nStart,int nLen) QYj*|p^x
{ Y .E.(\
int n = -1; ]DUmp6
try{ QFB2,k6jN
oSavedFile.write(b,nStart,nLen); _VB;fH$
n = nLen; 4j}.=u*X7
} @X2zIFm
catch(IOException e) ?AVnv(_
{ A4*D3\>%u
e.printStackTrace (); D;hJK-Y
} 6>3zD)tG
de9e7.(2
zjTCq; G
return n; E9w"?_A)
} IrIW>r} -
l*Q OM
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} iA|n\a~ny,
hh$i1n
4}Y? :R
/* L'$({
**SiteInfoBean.java =Qn8Y`U
*/ r3Kx
package NetFox; /g1;`F(MS/
~<}?pDA}~
o{' JO3
public class SiteInfoBean { ?k=)T]-}
YkQ=rurE
9 ge'Mo
private String sSiteURL; //Site's URL lmIphOUoIw
private String sFilePath; //Saved File's Path u`XZtF<vf
private String sFileName; //Saved File's Name #'m#Q6`
private int nSplitter; //Count of Splited Downloading File Pz|}[Cx-
3*F|`js"
&?I3xzvK
public SiteInfoBean() BwYR"
{//nSplitter的缺省值为5 *c(J4
//default value of nSplitter is 5 s]HJcgI
this("","","",5); Gx|/ Jq
} S] 4RGWn
r!^VCA
?'>[nm
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <J]N E|:
{ a~k*Gd(
sSiteURL= sURL; l xP!WP
sFilePath = sPath; {M23a _t\
sFileName = sName; 'N&s$XB,
this.nSplitter = nSpiltter; X;{U?`b-
;T<'GP'/r
mp0s>R
} =T$2Qo8
BOl*. t
P#/s5D8
public String getSSiteURL() Q@TeU#2Y
{ &!*p>Ns)e
return sSiteURL; >p3S,2SM
} }]pOR&o
0a+U >S#
C?rb}(m
public void setSSiteURL(String value) ']sIU;h3
{ "77l~3
sSiteURL = value; 2bf#L?5g/
} Ut(BQM>U+$
"-Uqv@
@ 3b-
public String getSFilePath() cMfnc.P\K
{ bR=TGL&
return sFilePath; Z"G?+gM@
} j[w5#]&%
nB |fw"
n* z;%'0
public void setSFilePath(String value) xQ=L2pX
{ ,f .#-
sFilePath = value; kCKCJ}N
} v8THJf
UmCIjwk
([hd
public String getSFileName() |H8UT SX+
{ qjRp5
return sFileName; Z-i$KF
} a]x\e{
Csm23QLsg)
FFc?Av?_
public void setSFileName(String value) z\<gm$1CB
{ 8=3$U+
sFileName = value; -<5H8P-
} d`KW]HJw
={nuz-3
-:V2Dsr6;
public int getNSplitter() f q*V76F
{ 68!=`49r>
return nSplitter; Z15b'^)?9
} 4hV~ ir
ulXe;2
KkZo|\V
public void setNSplitter(int nCount) D]Gt=2\NG9
{ `"|u NVn
nSplitter = nCount; ="[6Z$R
} m6 a@Y<
} Va\?"dH>M
B=2f-o
+'D #VG
/* "\kr;X'
**Utility.java D?cE$P
*/ n4EZy<~m
package NetFox; J]Qbg7|
[M:BJ%*
D^2yP~(
public class Utility { 7A>glZ/x
_+nlm5
o n?8l?iQ
public Utility() b.v^:M
{ 9,Ug
(2%z9W
@RS|}M^4
} CA ,0Fe3
J_ `\}55n
//线程睡眠 B ? D|B
public static void sleep(int nSecond) nL* SNQ_
{ ,m.IhnCV\
try{ !CuLXuM
Thread.sleep(nSecond); i9y&<^<W
} Y&`nB,'
catch(Exception e) btU:=6
{ @c{b\is2
e.printStackTrace (); o*|j}hnbv
} 2;=xHt
} <7sGA{
4O3-PU>N
//日志 gR) )K)
public static void log(String sMsg) l050n9#9p
{ $Z^HI
System.err.println(sMsg); . vQCX1V(
} T=->~@5
C9FQo7
8Dy;'BtT
public static void log(int sMsg) k-\RdX)E
{ }KwL_\>&f
System.err.println(sMsg); mw&)j R$&
} /CN`U7:E
} [P746b_\e
)k|_ CW~
]Syr{|
/* AIFI@#3
**TestMethod.java 6'qC *r
*/ m%km@G$
package NetFox; TwXqk>J
uVw|fT
-?68%[4lm_
public class TestMethod { -.X-02
<Xr{1M D
P ||:?3IH
public TestMethod() 'rQ>Z A_8
{ ///xx/weblogic60b2_win.exe :;]iUjiC8
try{ &?#G)suP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \4OX]{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?ydqmj2[F
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6S#e?>"+
fileFetch.start(); `aW>h8$I)
} u4a(AB>S
catch(Exception e){e.printStackTrace ();} 8/dx)*JCq
u:f.g?!`"
5L4{8X0X8
} 3KW4 ]qo~
gK8{=A0c
zn'F9rWx>
public static void main(String[] args) F"<TV&xf
{ &{c.JDO
new TestMethod(); hf~'EdU
} OWRT6R4v
} G&HCOR!h
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