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)); c]*yo
} R~=c1bpdq
for(int i=0;i<nEndPos.length-1;i++) >l0Qd1
{ =d;a1AO{&
nEndPos = nStartPos[i+1]; Jq^[^
} l7t
nEndPos[nEndPos.length-1] = nFileLength; (6fD5XtS
} 1feVFRx'
} Yup#aeXY/
tar/no
Ox)<"8M
//启动子线程 -o/Vp>_UOE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LuRCkKJ
for(int i=0;i<nStartPos.length;i++) / :$WOQ
{ x1~AY/)v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gYt=_+-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V dJ
nStartPos,nEndPos,i); ^qL<=UC.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'A[PUSEE
fileSplitterFetch.start(); .nY}_&
} K-'uE)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D&fOZVuqZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >FeCa hFn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Af\@J6viF7
nEndPos = " + nFileLength); EuHQp7
// fileSplitterFetch[nPos.length-1].start(); Lum=5zDo
EwBrOq`C
13@emb
//等待子线程结束 :"y2u
//int count = 0; h7eb/xEto
//是否结束while循环 bM'F8Fi
boolean breakWhile = false; +184|nJ<2
$\m:}\%p
h8WM4 PK
while(!bStop) LTf)`SN %'
{ <mJ8~
write_nPos(); vAP1PQX;
Utility.sleep(500); b|V<Kp
breakWhile = true; y:E$n!
=Fe4-B?I
{yNeZXA>
for(int i=0;i<nStartPos.length;i++) dOaOWMrfdf
{ [m! P(o
if(!fileSplitterFetch.bDownOver) y=Eb->a){
{ 3B]E2
breakWhile = false; *QN,wBQ
break; XnYX@p
} <XrXs
} ?yG[VW
if(breakWhile) a,fcKe&B
break; `j3 OFC{7E
xm=Gt$>.o
I>8_gp\1
//count++; D<70rBf2
//if(count>4) F^.]g@g.|
// siteStop(); U `lp56
} BJ_"FG
jcC"vr'u|
InL_JobE8r
System.err.println("文件下载结束！"); %4R1rUrgt|
} IPTFx )]G
catch(Exception e){e.printStackTrace ();} `#ff`j|a
} B3yTN6-
GsO(\hR6^
|)d%3s\
//获得文件长度 pcIS}+L
public long getFileSize() 2asRJ97qES
{ tW!*W?
int nFileLength = -1; $J<WFDn9
try{ %$Fe[#1
URL url = new URL(siteInfoBean.getSSiteURL()); ZG+FX:v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P@bPdw!JA
httpConnection.setRequestProperty("User-Agent","NetFox"); ~[F7M{LS
K20Hh7cVJ
h}tC+_"D
int responseCode=httpConnection.getResponseCode(); R:l&2
if(responseCode>=400) \(`2@
{ |7KWa(V5I
processErrorCode(responseCode); Sz|kXk6&9
return -2; //-2 represent access is error $[Ut])4 ~
} .p Mwa
ZJ+ad,?,
!Mgo~h"]#
String sHeader; EXbZ9 o*
Txl|F\nK`
6pb~+=3n
for(int i=1;;i++) R@uA4Al
{ )zy;!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <l!:#u
//Utility.log(in.readLine()); tZx}/&m-
sHeader=httpConnection.getHeaderFieldKey(i); /V cbT >=
if(sHeader!=null) Jza?DhSAZ
{ @+nCNXK
if(sHeader.equals("Content-Length")) ]H{*Z3S
{ gB%"JDn8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @ G!Ir"Q
break; RnC+]J+?4
} E 6MeM'sx
} J8@.qC'!
else >\~Er@
break; "*`!.9pt
} 2z$!}
} kVCWyZh4
catch(IOException e){e.printStackTrace ();} T12Zak4.=
catch(Exception e){e.printStackTrace ();} >S0kiGDV{
/oJ &\pI
FSz<R*2
Utility.log(nFileLength); m8 _yorz
M/lC&F(
KSS]%66Y
return nFileLength; R-<8j`[0
} |Vlx:
G{,DoCM5WL
E ?bqEW(
//保存下载信息（文件指针位置） - q(a~Ge
private void write_nPos() }/\`'LQ
{ p{v*/<.;
try{ Zl'/Mxg
output = new DataOutputStream(new FileOutputStream(tmpFile)); Dk$<fMS,7c
output.writeInt(nStartPos.length); @vib54G
for(int i=0;i<nStartPos.length;i++) 3*\Q]|SI!
{ SHB'g){P
// output.writeLong(nPos); WrRY3X
output.writeLong(fileSplitterFetch.nStartPos); BHU$QX
output.writeLong(fileSplitterFetch.nEndPos); {jwLVKT$
} x)N QRd
output.close(); N5`z S79W
} ?F!c"+C
catch(IOException e){e.printStackTrace ();} Qv'x+GVW]
catch(Exception e){e.printStackTrace ();} 4M]l~9;A
} ZNDi;6e
0s{7=Ef
u>vvW|OB[
//读取保存的下载信息（文件指针位置） }kItVx
private void read_nPos() n'q:L(`M
{ K0B<9Wi|
try{ Fv)E:PnKC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MwQ4&z#wh
int nCount = input.readInt(); O^6anUV0
nStartPos = new long[nCount]; _!vy|,w@e
nEndPos = new long[nCount]; =-r); d
for(int i=0;i<nStartPos.length;i++) |N)),/R_
{ |*b-m k
nStartPos = input.readLong(); L AA(2
nEndPos = input.readLong(); XpkOCo02
} UU[z\^w| E
input.close(); zG/? wP"
} &Ruq8n<
catch(IOException e){e.printStackTrace ();} mvTp,^1
catch(Exception e){e.printStackTrace ();} !J!&JQ|
} _emW#*V
n53c}^
3HuGb^SNg
private void processErrorCode(int nErrorCode) @x743}Y\
{ QS\wtTXj
System.err.println("Error Code : " + nErrorCode); P zM yUv
} FIVC~LDd
k.c.7%|~;
S3WUccv
//停止文件下载 2P^qZDG 8I
public void siteStop() j`$$BVZ
{ .L"IG=Uh#
bStop = true; $)X8'1%6
for(int i=0;i<nStartPos.length;i++) u3,O)[qV
fileSplitterFetch.splitterStop(); Uey'c1
HOCj* O4
v@M^ukk'}
} /K1cP>oE
} ZMiOKVl
//负责部分文件的抓取 < FO=PM
**FileSplitterFetch.java 1kUlQ*[<|
*/ liLhvcd
package NetFox; %m[ZU<v
hOj+z?
f^"pZS
import java.io.*; f.66N9BHL,
import java.net.*; kQlwl9
N]|>\
t&[<Dl/L
public class FileSplitterFetch extends Thread { >nih:5J,ja
H=f|X<8
]b sabS?
String sURL; //File URL M3|G^q:l
long nStartPos; //File Snippet Start Position dkCUU
long nEndPos; //File Snippet End Position '6>*J
int nThreadID; //Thread's ID <LXx_{=:
boolean bDownOver = false; //Downing is over SZ$WC8AX
boolean bStop = false; //Stop identical v3XM-+Z4
FileAccessI fileAccessI = null; //File Access interface 10c.#9$
,5ZQPICF
=8<~pr-NO
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3b]M\F9
{ R)\^*tkz7
this.sURL = sURL; +DR$>a
this.nStartPos = nStart; d(ypFd9z
this.nEndPos = nEnd; T{f$S
nThreadID = id; [>\|QS|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]PoWL;E'
} a@qc?
8=joVbs
udLIAV*
public void run() u-4@[*^T$
{ vW vu&3tx
while(nStartPos < nEndPos && !bStop) DU]KD%kl
{ VHl1f7%@H
6W=V8
7C3YVm6g
try{ btq4diW
URL url = new URL(sURL); 4sn\UuKyL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x(eX.>o\
httpConnection.setRequestProperty("User-Agent","NetFox"); bGgpPV
String sProperty = "bytes="+nStartPos+"-"; e3:L]4t
httpConnection.setRequestProperty("RANGE",sProperty); o,*D8[
Utility.log(sProperty); ~eoM 2XlW
09G47YkSy1
<.gDg?'3
InputStream input = httpConnection.getInputStream(); GfEWms8z
//logResponseHead(httpConnection); m}=E$zPbO
GbL1<P$V
9jEH"`qqk
byte[] b = new byte[1024]; h3 XSt
int nRead; 0*rD'?)K+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Pn[oo_)s
{ ]SRpMZ
nStartPos += fileAccessI.write(b,0,nRead); HBtk)
//if(nThreadID == 1) ]- `wXi"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \y=oZk4
} q^EY?;Y
DmLx"%H3
|3@DCbT
Utility.log("Thread " + nThreadID + " is over!"); 9_O4yTL
bDownOver = true; A!x&,<
//nPos = fileAccessI.write (b,0,nRead); a6e{bAuq
} Q-gVg%'7
catch(Exception e){e.printStackTrace ();} mJk\$/Kh
} )(-;H|]?
} gC/ e]7FNr
Uza '%R
:Z6j5V;s
//打印回应的头信息 >5L_t
public void logResponseHead(HttpURLConnection con) ~qGW94
{ @CL#B98jl
for(int i=1;;i++) 1H/I-
{ {o)pwM"@(
String header=con.getHeaderFieldKey(i); ^9q#,6
if(header!=null) g;8 wP5i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Em@:QmEN
Utility.log(header+" : "+con.getHeaderField(header)); 9iZio3m
else B<m0YD?>~>
break; 0zq'Nf?#3
} #m{*]mY@
} <TRhnz
5j1d=h
NBc^(F"
public void splitterStop() '"\M`G
{ k<^M >` $
bStop = true; &EQhk9j
} LtMM89u
$%cc[[/U
9 =;mY
} 4#03x:/<\
'!Hs"{~{
6,3o_"J!
/* crP2jF!
**FileAccess.java d"#Zp&#
*//文件访问(定位，写) !ou#g5Q@z
package NetFox; ~,HFd`
import java.io.*; qEST[S V
mSxn7LG
?s^3o{!<W
public class FileAccessI implements Serializable{ TD}<U8I8_
cA q3Gh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0^-1d2Z~
RandomAccessFile oSavedFile; WxGD*%
long nPos; &HM-UC|
w#9KtW,tt
=L" 0]4K
public FileAccessI() throws IOException PFh ^Z L
{ /^BC Qaj
this("",0); =79R;|5
} Z,38eQpM
0d9z8y
8I#ir4z#<
public FileAccessI(String sName,long nPos) throws IOException ]19VEH
{ 2L^)k?9>g+
oSavedFile = new RandomAccessFile(sName,"rw"); @ivd|*?k0
this.nPos = nPos; L9D`hefz
oSavedFile.seek(nPos); d7X&3L%Oq
} K}R+~<bIY
'RK"/ZhqE
PX 8UVA
public synchronized int write(byte[] b,int nStart,int nLen) r<e%;S
{ 5XZ!yYB?
int n = -1; oY18a*_>M1
try{ }p7iv:P=3
oSavedFile.write(b,nStart,nLen); }6c>BU}DF
n = nLen; (hzN(Dh
} ump~)?_B
catch(IOException e) KT(Z #$
{ 6@J=n@J$p
e.printStackTrace (); ZYwcB]xEz
} WD[eoi
7w/IHML
#dA$k+3
return n; \WCQ>c?~
} I9*cEZ!l=e
n~*".ZC'Y
%X{EupiFA
} @Iv;y*y
$RPW/Lyiq
}~XWtWbd-
/* 'jtC#:ePK
**SiteInfoBean.java Wp=3heCa6
*/ )\fY1WD
package NetFox; f&^(f1WO
pIJXP$v3
+$,Re.WnP
public class SiteInfoBean { O<gfZ>
k&]nF,f
Z',!LK!
private String sSiteURL; //Site's URL Ma[EgG
private String sFilePath; //Saved File's Path &7aWVKon
private String sFileName; //Saved File's Name e`D}[G#
private int nSplitter; //Count of Splited Downloading File /~[Lr
6Xlzdt
~7P)$[
public SiteInfoBean() W7i|uTM
{//nSplitter的缺省值为5 t;&XIG~
//default value of nSplitter is 5 NI >%v
this("","","",5); 4>hHUz[_
} aLJm%uW6m&
g{65QP
*gbK :*_J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \c=I!<9
{ {*ak>Wud
sSiteURL= sURL; $cCC 1=dW
sFilePath = sPath; [. 5m}V
sFileName = sName; T #\
this.nSplitter = nSpiltter; "ZuuSi
x*Lt]]A
ff"wg\O4
} %@/^UE:
'$K E=Jy
jVj5; }
public String getSSiteURL() XIeLu"TSL
{ ~Iu!B Y
return sSiteURL; ^:eZpQ [,
} ;;Q^/rkC
)O]T}eI
WSkGVQu
public void setSSiteURL(String value) =l,P'E
{ AlSO
sSiteURL = value; xt{'Be&Ya+
} +L(amq;S
&NE e-cb[
EdJL&*
public String getSFilePath() )D)5 `n)
{ /:&!o2&1H
return sFilePath; l>?c AB[
} p*Bty@CRi
hRcb}>pr
7|P kc(O
public void setSFilePath(String value) U@lc1#
{ NR{wq|"
sFilePath = value; &1xCPKIr
} aER|5!7(2\
9(CvGzco<
|y\Km
public String getSFileName() OZ,kz2SF#
{ /HC:H,"i
return sFileName; [m t.2.
} f^WTsh]
--$o$EP`
1^p/#jt
public void setSFileName(String value) '=\}dav!
{ h~MV=7 lE
sFileName = value; Y Y:BwW:
} f& 4_:'-,
JE?p'77C
$Gn.G_"v
public int getNSplitter() e%4?-{(
{ TOYK'|lwM
return nSplitter; z3fv}_\z
} bf3!|Um
yqK4 "F&
qfkHGW?1/j
public void setNSplitter(int nCount) |.IH4 K
{ Pf?kNJ*Tv)
nSplitter = nCount; *dzZOe>,
} KaGUpHw
} "cH RGJG#
"q4tvcK.
B{-7
/* D7ex{SVA)
**Utility.java # kI>
*/ R#(0C(FI^
package NetFox; F /b`[
X>%nzY]m
W+XWS,(
public class Utility { 7\u+%i;YZ
zd?@xno
jjpYg
public Utility() *OVB;]D3+
{ 6Z/`p~e
+)Te)^&v%
Z5{a7U4z_
} &dtk&P{
Ycm)PU["
//线程睡眠 R+sT &d
public static void sleep(int nSecond) @nxo Bc !P
{ R{hX--|j
try{ bIKg>U'5d
Thread.sleep(nSecond); ]m]`J|%i
} bP,<^zA|X
catch(Exception e) 'Pz%c}hJ
{ ]AP1+ &9fN
e.printStackTrace (); #XV=,81w
} Er~17$b
} 8WP>u8&
dWY%bb
//日志 &}ZmT>q`$
public static void log(String sMsg) D{|qP nE4
{ <QtZ6-;_f
System.err.println(sMsg); fF:57*ys
} -F[8ZiZ
8$Q`wRt(%
?-??>& z
public static void log(int sMsg) .@dC]$2=
{ U%{GLO
System.err.println(sMsg); wI#8|,]"z
} A#uU]S
} WlL(NrVA@@
2FcL-?
4Nm>5*]
/* }E`Y.= S
**TestMethod.java 3f|}p{3
*/ b`0tfXzS5
package NetFox; L aTcBcI
` ]|X_!J-
UuG%5 ZC
public class TestMethod { ! VwU=5
Xo^8o0xi
AXfU$~
public TestMethod() ,OZ
{ ///xx/weblogic60b2_win.exe h\RX/C!+
try{ p_r`"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $QX$rN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @xG&K{j
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?7{U=1gb$
fileFetch.start(); 5Z=4%P*I
} *%-<Ldv
catch(Exception e){e.printStackTrace ();} .soCU8i3
EZtU6kW"
Xj?Wvt
} ~{x1/eH
~%hdy@
` Xc7b
public static void main(String[] args) D?|D)"?qb
{ %zavSm"
new TestMethod(); S :HOlJze
} ,(jJOFf
} {1GJ,['qL
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