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)); %Uk]e5Hu
} Z7&Bn
for(int i=0;i<nEndPos.length-1;i++) zmI?p4,
{ XfFZ;ul
nEndPos = nStartPos[i+1]; C%<[mM
} 2U6j?MyH2
nEndPos[nEndPos.length-1] = nFileLength; yi3@-
} @>'.F<:P<
} K;2tY+I
vVF#]t b|
4*9y4"
//启动子线程 /ey[cm2#[s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9V&%_.Z
for(int i=0;i<nStartPos.length;i++) FJ3Xeos4|
{ $l:?(&u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pmAir:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5fS89?/?
nStartPos,nEndPos,i); jp2AU,Cl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )J+vmY~&
fileSplitterFetch.start(); iq`y
} zzfwI@4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r=dFk?8XbC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S86%o,Saq\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uY;-x~Z
nEndPos = " + nFileLength); 7SE=otZ>
// fileSplitterFetch[nPos.length-1].start(); 7>EjP&l
IMzhEm
eRllF`*
//等待子线程结束 EAq/Yw2$
//int count = 0; LV{a^!f`y
//是否结束while循环 }5^j08
boolean breakWhile = false; j'i-XIs
d[z+/L
:0pxacD"!
while(!bStop) ^ MkT">
{ 6.|f iQs]
write_nPos(); fRJSo%
Utility.sleep(500); s%`o
breakWhile = true; b w5|gmO
6Gjr8
NS"hdyA
for(int i=0;i<nStartPos.length;i++) Ftj3`Mu
{ S~`&K
if(!fileSplitterFetch.bDownOver) w5|az6wZB!
{ d|5u<f5
breakWhile = false; /EhojODMF
break; pLL ^R
} Dq+rEt
} 67 >*AL
if(breakWhile) L's_lC
break; C^RO@kM
NMY~f (x
uD_|/(
//count++; 39?iX'*p
//if(count>4) T$13"?sr=
// siteStop(); '.oEyZA;o
} f+Nq?GvwBQ
CDei+ q
'6u;KIG
System.err.println("文件下载结束！"); I'G$:GX
} o9~Z! &p
catch(Exception e){e.printStackTrace ();} KcP86H52I
} ZbCu -a{v
DGdSu6s$
~q#UH'=%
//获得文件长度 zLuej'
public long getFileSize() Zr'VA,v
{ ihKnZcI$i
int nFileLength = -1; y1^<!I
try{ NvXds;EC
URL url = new URL(siteInfoBean.getSSiteURL()); VN|P(S6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R<)7,i`F
httpConnection.setRequestProperty("User-Agent","NetFox"); YVZm^@ZVV
GWRKiTu9
6w<jg/5t
int responseCode=httpConnection.getResponseCode(); ]1rr$f9
if(responseCode>=400) RUm1;MWs
{ Fsv%=E{
processErrorCode(responseCode); 31k.{dnm
return -2; //-2 represent access is error C/ow{MxA
} 9f;\fe
|"DQ^)3Pi
Q u2W
String sHeader; 21M@z(q*
/og2+!
l,HMm|oU
for(int i=1;;i++) azz6_qk8
{ u\-xlp?"o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ( du<0J|PT
//Utility.log(in.readLine()); D_`MeqF}C
sHeader=httpConnection.getHeaderFieldKey(i); tlu-zUsi
if(sHeader!=null) PoY+Y3
{ >F6'^9|
if(sHeader.equals("Content-Length")) e?3 S0}
{ D#508{)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); UyBI;k^]
break; W"YFx*W
} t.c XrX`k
} &%L1n?>Q}
else ^rjICF e
break; \kZxys!4
} cF3V{b|bU
} y^=\w?d
catch(IOException e){e.printStackTrace ();} &V$_u#<
catch(Exception e){e.printStackTrace ();} (}vi"mCeW
bNp RGhlV
a_w#,^/P
Utility.log(nFileLength); l~Hs]*jm
?8fa/e
v/\l
return nFileLength; :CNWHF4$
} ZY+NKb_
4StiYfae
0RN]_z$;H
//保存下载信息（文件指针位置） z%(m:/N70
private void write_nPos() 9a"[-B:
{ `] ;*k2
try{ ^aN;M\
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?SRG;G1
output.writeInt(nStartPos.length); kJq8"Klg
for(int i=0;i<nStartPos.length;i++) xq-R5(k
{ 4!,x3H'
// output.writeLong(nPos); #GT/Q3{C
output.writeLong(fileSplitterFetch.nStartPos); ir-srVoXy
output.writeLong(fileSplitterFetch.nEndPos); )8p FPr
} 4*d$o=wa
output.close(); (eS4$$g
} &z8@ rk|
catch(IOException e){e.printStackTrace ();} x6\EU=,
catch(Exception e){e.printStackTrace ();} Y` Oz\W
} ,IF3VE&r
i[sHPEml(5
vdAaqM6D
//读取保存的下载信息（文件指针位置） ='a[(C&Y
private void read_nPos() qasbK:}
{ thIuK V{CO
try{ BSYJ2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pqli3(
int nCount = input.readInt(); 3#`_t :"A
nStartPos = new long[nCount]; S*VG;m#
nEndPos = new long[nCount]; ?%dsY\
for(int i=0;i<nStartPos.length;i++) ET;YAa*
{ C;];4[XR
nStartPos = input.readLong(); d5T M_C
nEndPos = input.readLong(); ~CCRs7V/L
} 1p=^I'#
input.close(); MdmS
} {.qeVE{
catch(IOException e){e.printStackTrace ();} G?)NDRM
catch(Exception e){e.printStackTrace ();} <]xGd!x$
} _>+!&_h
q@8Jc[\d
=~6A c}$
private void processErrorCode(int nErrorCode) 6^y*A!xY
{ s(jixAf
System.err.println("Error Code : " + nErrorCode); j\k|5="w-
} ;NQ9A &$)
9z6-HZG'~<
g|ewc'y
//停止文件下载 5&Al
public void siteStop() W{:^P0l
{ gpDH_!K
bStop = true; 4v9jGwnzt
for(int i=0;i<nStartPos.length;i++) /5 yjON{
fileSplitterFetch.splitterStop(); &u&+:m
X)^eaw]Q0
wd*8w$\
} 9"hH2jc
} + 2v6fan
//负责部分文件的抓取 15dhr]8E
**FileSplitterFetch.java pW$ZcnU
*/ Ey96XJV
package NetFox; V,:^@ 7d
~A^E_
dZ}gf}.v
import java.io.*; @i2"+_}*
import java.net.*; /iURP-rl
3'tcEFkH
_#32hAI
public class FileSplitterFetch extends Thread { p_%dH
HR'sMu3
Pt< JF
String sURL; //File URL U[7 &
long nStartPos; //File Snippet Start Position Sv3O${B|
long nEndPos; //File Snippet End Position w3l2u1u
int nThreadID; //Thread's ID OBY^J1St
boolean bDownOver = false; //Downing is over )+ifVv50
boolean bStop = false; //Stop identical HXV4E\JA
FileAccessI fileAccessI = null; //File Access interface &JMp)zaI[
:Ywb
8LuM eGs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >}<1
{ SFqY*:svOw
this.sURL = sURL; 8R|!$P
this.nStartPos = nStart; h;" 9.
this.nEndPos = nEnd; W D8
nThreadID = id; j=|cx+nb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p1tqwV
} IE*eDj
h pf,44Kg
c_"=G#^9@i
public void run() 0b=1Ce+0q
{ 3Ye{a<ckK
while(nStartPos < nEndPos && !bStop) _EPfeh;
{ ;::]R'F[
|m{u]9
@vyq?H$U;N
try{ YoDL/
URL url = new URL(sURL); ri.}G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); phCItN;
httpConnection.setRequestProperty("User-Agent","NetFox"); aF8'^xF
String sProperty = "bytes="+nStartPos+"-"; B|WM;Y^
httpConnection.setRequestProperty("RANGE",sProperty); H@,h$$
Utility.log(sProperty); +G:CR,Z>+
6_mkt|E=
i?{)o]i
InputStream input = httpConnection.getInputStream(); KXrZ:4bg
//logResponseHead(httpConnection); jxc^OsYj
_:+hB9n s
*Aqd["q
byte[] b = new byte[1024]; L(RI4d
int nRead; W kP`qD3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) trx y3k;
{ 6W\G i>
nStartPos += fileAccessI.write(b,0,nRead); LX'z7fh
//if(nThreadID == 1) m&MAA^I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [?>\]
} &&PXWR!%]
-v %n@8p
px${ "K<
Utility.log("Thread " + nThreadID + " is over!"); .9NYa|+0
bDownOver = true; n2A ; `=
//nPos = fileAccessI.write (b,0,nRead); {,+{,Ere
} WuuF&0?8C
catch(Exception e){e.printStackTrace ();} '3|fv{I
} { )g $
} S(^HIJK
MCO2(E-
,ZV>"'I:
//打印回应的头信息 7Is:hx|:
public void logResponseHead(HttpURLConnection con) ]9$iUA%Ef
{ a^o'KN{
for(int i=1;;i++) LvqWA}
{ )FpizoVq0
String header=con.getHeaderFieldKey(i); *fCmZ$U:{
if(header!=null) q0C%">>1#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d/Sw.=vq
Utility.log(header+" : "+con.getHeaderField(header)); @WCA7DW!
else nEt{ltsS0
break; ;Zm-B]\
} h6b(FTC^
} H)k V8wU
QHXA?nBX
baoyU#X9
public void splitterStop() +)hxYLk&I
{ uf^HDrr<L
bStop = true; `r'$l<(4WV
} =`ZRPA!aY
hmkm^2
=Y-.=}jp;
} 5OCt Q4u
$b~[>S-Q
2@N9Zk{{J
/* ZsNZ3;d@u(
**FileAccess.java ZEK,Z['
*//文件访问(定位，写) OO2uE ;( 3
package NetFox; S]&:R)#@
import java.io.*; n$rgJ
Xub*i^(]
u69UUkG
public class FileAccessI implements Serializable{ OdbXna
ff;~k?L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 esiU._:u
RandomAccessFile oSavedFile; D0Mxl?S?
long nPos; &,P; 7R
a&2UDl%K
I_m3|VCa|t
public FileAccessI() throws IOException 5Gs>rq" #
{ [D+,I1u2h
this("",0); fGd1
} ppo0DC\>
9 JhCSw-<)
u`ryCZo#g
public FileAccessI(String sName,long nPos) throws IOException k;B[wEW@
{ ]$uC~b
oSavedFile = new RandomAccessFile(sName,"rw"); A`#?Bj
this.nPos = nPos; eBH:_Ls_-^
oSavedFile.seek(nPos); dF[|9%)
} d>?C?F
9Fy'L#%
HSWki';G
public synchronized int write(byte[] b,int nStart,int nLen) {+m8^-T
{ ,CI-IR2
int n = -1; a>6D3n W
try{ Q6HghG
oSavedFile.write(b,nStart,nLen); #UE}JR3g
n = nLen; 'ieTt_1.G
} !Rc %
catch(IOException e) cQ]c!G|a4
{ k'_f?_PBu
e.printStackTrace (); h% KEg667
} r.'xqzF/
@ x .`z
;Xf1BG r
return n; c`/VYgcTqB
} soLW'8
9%Tqk"x?
Zs]n0iwM'@
} {sf ,(.W
HUMy\u84H
gV-*z}`U
/* u]Q}jqiq"
**SiteInfoBean.java +;\w'dBi,
*/ }K={HW1>
package NetFox; sE'c$H
b*(K;`9)B
8Ji`wnkXe
public class SiteInfoBean { j^5YFUwsQg
[-VK!9pQ
Qu1&$oO
private String sSiteURL; //Site's URL v)T# iw[
private String sFilePath; //Saved File's Path B~E">}=!
private String sFileName; //Saved File's Name @dk-+YxG
private int nSplitter; //Count of Splited Downloading File Vz$xV!
M(nzJ
?HRS*
public SiteInfoBean() "-djA,`
{//nSplitter的缺省值为5 Pro?xY$E)
//default value of nSplitter is 5 %.hJDX\j
this("","","",5); up+0-!AH
} dOKp:|9G
<{k`K[)
ZG0^O"B0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6}m`_d?
{ Lu{/"&)
sSiteURL= sURL; G^tazAEfo
sFilePath = sPath; :'B(DzUR
sFileName = sName; SzIzQR93&
this.nSplitter = nSpiltter; Q 8Hl7__^
PDPK|FU
P))BS
} p5$}h,7
[.^ol6
&9^4-5]
public String getSSiteURL() +WAkBE/
{ S't9F
return sSiteURL; .hu7JM+
} 9DJ&J{2W
zt: !hM/Vt
S9Oz5_x
public void setSSiteURL(String value) Dm{Xd+Y
{ o5p{ O>D[z
sSiteURL = value; O-HS)g$2
} &BLCP d
J}&U[ds p
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public String getSFilePath() :>.{w$Ln%
{ "d:rPJT)(@
return sFilePath; W03mdRW
} 1$eoW/8.
F$DA/{.D
bJetqF6n
public void setSFilePath(String value) X5YOxMq
{ t$(#$Z,RS
sFilePath = value; CDM6o!ur3
} _\KFMe=PV
WM`3QJb
COsmVQ.
public String getSFileName() d_d&su E
{ =TDKU
return sFileName; ~1D^C |%
} r) x
bwzx_F/
&muBSQ-
public void setSFileName(String value) ru@#s2
{ PkrVQH9^w
sFileName = value; U!o7Nw@z
} ;.Bz'Q
ns%gb!FBJX
:-}K:ucaj
public int getNSplitter() pe vXixl
{ {o5|(^l
return nSplitter; k7Bh[ ..!
} )`rD]0ua;
I4G0!"T+
y Ne?a{
public void setNSplitter(int nCount) 5aizWz
{ T8a' 6otc
nSplitter = nCount; y<kUGsD
} RbL?(
} ,Q56A#Y\
@KK6JyOTQ
U}5fjY
/* =}#yi<Lt
**Utility.java JY2<ECO
*/ `jGeS[FhR
package NetFox; xcr2|
GMJ4v S
0TmEa59P
public class Utility { $KYGQP
WVRIq'
>t3_]n1e
public Utility() VKl,m ;&N
{ )vS0Au^C~
RFL* qd4
e&;e<6l&{
} ]0."{^ksL
uK@d?u!`
//线程睡眠 Ob/)f)!!
public static void sleep(int nSecond) y017 B<Ou
{ 6?F88;L
try{ &N^~=y^`C'
Thread.sleep(nSecond); _ l|%~
} IFTNr2I
catch(Exception e) 20V~?xs~
{ Zu,:}+niU
e.printStackTrace (); %PYO9:n
} :s_>y_=g
} K>DN6{hnV;
j**[[
//日志 vHf)gi}O|
public static void log(String sMsg) =$J(]KPv!?
{ 4CF;>b f~
System.err.println(sMsg); -5b|nQuY
} =@Oo3*>
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)k=KLQ\b
public static void log(int sMsg) :')[pO_FW*
{ ]gq)%T]
System.err.println(sMsg); oh8:1E,I
} @e)}#kN.
} f256;3n
X%'z
_/LGGt4&%
/* f\hMTebma$
**TestMethod.java ]?4;Lw
*/ A0Mjk
package NetFox; pX_#Y)5
tLy:F*1i
^xa, r#N:V
public class TestMethod { R'v~:wNTNs
&IQ=M.!r
uI-T]N:W8x
public TestMethod() 2|>\A.I|=
{ ///xx/weblogic60b2_win.exe 9~Dg<wQ
try{ z?\it(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KQPu9f9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @PvO;]]%
SiteFileFetch fileFetch = new SiteFileFetch(bean); o^@"eG$,
fileFetch.start(); 'GJB9i+a^
} \C3I6Qx
catch(Exception e){e.printStackTrace ();} XYo,5-
!kE5]<H\
5!F;|*vC8
} E%`J=C}
p/<DR|
]lC%HlID
public static void main(String[] args) Xfc$M(a K{
{ (L/>LZn|
new TestMethod(); &'z_:Wm
} UTkPA2x
} }/a%-07R
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