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)); 9MQ!5Zn
} e^)+bmh
for(int i=0;i<nEndPos.length-1;i++) N t]YhO
{ q}[g/%
nEndPos = nStartPos[i+1]; W($}G_j[B1
} 4RCD<7
nEndPos[nEndPos.length-1] = nFileLength; SJb+:L>
} egMl(~D
} RKoM49W
`)Z"||8K
J jRz<T;
//启动子线程 f%fD>a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2Wwzcvs@
for(int i=0;i<nStartPos.length;i++) @v^;,cu'8
{ -`nQa$N-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xE.K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xj8yQ Y1
nStartPos,nEndPos,i); 0$)uOUVJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HBHDu;u
fileSplitterFetch.start(); \$GM4:R D
} 5VD(fW[OW]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !n9H[QP^9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 04ZP\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }71a3EUK
nEndPos = " + nFileLength); \ng!qN
// fileSplitterFetch[nPos.length-1].start(); `}t<5_
+XV7W=
Y+vG]?D
//等待子线程结束 Dv~W!T i
//int count = 0; 0LEJnl
//是否结束while循环 84g$V}mp
boolean breakWhile = false; jcrLUs+\
Jg} w{,
'sb&xj`d
while(!bStop) a;a^- n|D
{ !'|^`u=eL
write_nPos(); cP#vzFB0>
Utility.sleep(500); Jbv66)0M
breakWhile = true; cAFYEx/(
M)sM G C
$*N^bj
for(int i=0;i<nStartPos.length;i++) *AK{GfP_
{ Kvx~2ZMx6
if(!fileSplitterFetch.bDownOver) .nDB{@#
{ Z:>)5Z{'
breakWhile = false; t}FwS6u
break; n hT%_se4
} mhh^kwW
} fXNl27c-
if(breakWhile) ca )n*SD
break; u^2)oL
kAc8[Hn
[;6,lI}
//count++; C_CUk d[
//if(count>4) (*qMs)~]B
// siteStop(); fcaUj9qN
} *CtWDUxSdW
vwF#;jj\
O_vCZW a3
System.err.println("文件下载结束！"); KHnq%#
} tqok.h
catch(Exception e){e.printStackTrace ();} f/"?(7F
} 73C7g< Mx
Fsdp"X.
~9Xs=S!
//获得文件长度 +95: O 8
public long getFileSize() V46=48K.
{ [f._w~
int nFileLength = -1; 3[_zz;Y*d
try{ 1u`{yl*+?
URL url = new URL(siteInfoBean.getSSiteURL()); +\s32o zg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6gr?#D -F
httpConnection.setRequestProperty("User-Agent","NetFox"); MSQz,nn
{>EM=ZZfg
hCpX#rg?
int responseCode=httpConnection.getResponseCode(); nDG41)|
if(responseCode>=400) W20qn>{z
{ Qqm$Jl!
processErrorCode(responseCode); KOv?p@d
return -2; //-2 represent access is error @wVq%GG}
} P5?M"j0/^
qoZUX3{
6h5DvSO
String sHeader; $3yzB9\a"
%imI.6
ve3-GWT{C
for(int i=1;;i++) tBB\^xq:
{ Hl|EySno
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -F->l5
//Utility.log(in.readLine()); cc0e(\
sHeader=httpConnection.getHeaderFieldKey(i); {tKi8O^Rb
if(sHeader!=null) %[l#S*)~
{ au+6ookT
if(sHeader.equals("Content-Length")) a ]b%v9
{ @Z+(J:Grm5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $!LL
break; Uo]x6j<
} F/ si =%
} 5w9oMM{
else :Vnus @#r
break; T[(4z@d`5
} a_V.mu6h6p
} S\jIs[Dz
catch(IOException e){e.printStackTrace ();} 9coN >y
catch(Exception e){e.printStackTrace ();} }LA7ku
+$CO
(_ TKDx_
Utility.log(nFileLength); qA;!Pql`
y+aL5$x6
b<E0|VW
return nFileLength; 9JtPP
} EJByYk
M[:},?ah0
[&MhAzF
//保存下载信息（文件指针位置） -dO9y=?t
private void write_nPos() .9uw@Eq
{ `VL<pqPP
try{ >Y)FoHa+/
output = new DataOutputStream(new FileOutputStream(tmpFile)); &al\8
output.writeInt(nStartPos.length); SbYsa
for(int i=0;i<nStartPos.length;i++) mo*ClU7
{ +)<H,?/
// output.writeLong(nPos); b%_[\((
output.writeLong(fileSplitterFetch.nStartPos); +Rq7m]
output.writeLong(fileSplitterFetch.nEndPos); "k>;K,:
} ~IQ2;A
output.close(); IEj=pI
} ,b${3*PPQ
catch(IOException e){e.printStackTrace ();} |M$ESj4@
catch(Exception e){e.printStackTrace ();} w+Oo-AGNH
} k2Dq~zn
@C"w 1}
;p8,=w
//读取保存的下载信息（文件指针位置） ~i5t1
private void read_nPos() =N?K)QD`
{ ;n2b$MB?nM
try{ tj<0q<is
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p+.{"%
int nCount = input.readInt(); 6>e YG<y{
nStartPos = new long[nCount]; {)y8Y9G
nEndPos = new long[nCount]; F#>^S9Gml
for(int i=0;i<nStartPos.length;i++) 6v(;dolBIw
{ =JDa[_lpN
nStartPos = input.readLong(); sqjv3=}
nEndPos = input.readLong(); ,0fYB*jk
} :/6gGU>pu
input.close(); dt1,!sHn
} )K>2
catch(IOException e){e.printStackTrace ();} yS"; q
catch(Exception e){e.printStackTrace ();} |)pgUI2O[
} gU%R9
fs3jPHZJ#
}DzN-g<K
private void processErrorCode(int nErrorCode) ;FH_qF`.
{ i9B1/?^W&
System.err.println("Error Code : " + nErrorCode); iTpK:pX
} s]@k,%
<uL0M`u3
15U[F0b
//停止文件下载 >&DNxw
public void siteStop() @;P\`[(*
{ 0o*
bStop = true; ;Y"*Z2U
for(int i=0;i<nStartPos.length;i++) d_!lRQ^N
fileSplitterFetch.splitterStop(); 5;yVA
Y:3\z?oV[
FZJyqqA$_
} \-scGemH
} qE)G;Y<,1
//负责部分文件的抓取 <CM}g4Y
**FileSplitterFetch.java w@Gk#
*/ .:?cU#.
package NetFox; 6H:'_|G
Xw<5VIAHm;
^[u*m%UB
import java.io.*; B>{\qj)%
import java.net.*; F3,djZq
KRN{Ath.
2Hj;o
public class FileSplitterFetch extends Thread { ?:1)=I<A4
]Yd7
d*(wU>J '
String sURL; //File URL \[5mBuk
long nStartPos; //File Snippet Start Position +/Vi"
long nEndPos; //File Snippet End Position [-*8S1
int nThreadID; //Thread's ID K"U!SWv
boolean bDownOver = false; //Downing is over p(-EtxP
boolean bStop = false; //Stop identical ]heVR&bQ
FileAccessI fileAccessI = null; //File Access interface xi=0kO
(/^?$~m"
GPizR|}h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~$ Po3]{s
{ E^Ch;)j|
this.sURL = sURL; mN l[D
this.nStartPos = nStart; PZvc4
this.nEndPos = nEnd; 3s?ZyQy
nThreadID = id; KYyoN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q@|"xKa
} @NiLKcL#
\Unawv~
<Qr*!-Kc6
public void run() elR1NhB|p
{ -]-0]*oAp
while(nStartPos < nEndPos && !bStop) &> _aY #
{ m;nH v
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[VLq/lg*
try{ ;dtA-EfOZ
URL url = new URL(sURL); fLeHn,*,"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q,_EHPc
httpConnection.setRequestProperty("User-Agent","NetFox"); N?8nlrDQ
String sProperty = "bytes="+nStartPos+"-"; Q-A_8
httpConnection.setRequestProperty("RANGE",sProperty); iaQfxQP1w%
Utility.log(sProperty); EiP N44(
@My RcC
&xvNR=K[`
InputStream input = httpConnection.getInputStream(); E:O/=cT
//logResponseHead(httpConnection); e\O625
\ KsKb0sM
eA3NyL
byte[] b = new byte[1024]; l: kW|
int nRead; GY5JPl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xOr"3;^
{ O>I%O^
nStartPos += fileAccessI.write(b,0,nRead); =(~*8hJ
//if(nThreadID == 1) a^^OI|?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {u0sbb(
} <WbO&;%
S;/pm$?/
!]9qQ7+R%
Utility.log("Thread " + nThreadID + " is over!"); tR4+]K
bDownOver = true; >p#_L^oZ%
//nPos = fileAccessI.write (b,0,nRead); OlptO60{ ]
} D+N@l"U{
catch(Exception e){e.printStackTrace ();} _RS CyV
} fGW~xul_
} Ic^ (6
.Wi%V"
[w-# !X2y
//打印回应的头信息 ?!$Dr0r
public void logResponseHead(HttpURLConnection con) 0'Qvis[kt
{ !s !el;G
for(int i=1;;i++) KNN$+[_;H4
{ hD7vjg&Z
String header=con.getHeaderFieldKey(i); ^jcVJpyT@R
if(header!=null) "Er8RUJA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "HwlN_PA
Utility.log(header+" : "+con.getHeaderField(header)); =EH/~NGk
else a[,p1}!_
break; l)~$/#k
} h#dfhcU>
} 5Vdy:l
1(_[awBx
Su[(IMw
public void splitterStop() E$A=*-u
{ @7;}6,)
bStop = true; h`eHoKJ#w
} |eFaOL|
'*Tt$0#o
ynf!1!4
} &OkPO|
_PQk<QZ
<]_[o:nOP
/* ^rO!-
**FileAccess.java }[PC YnS
*//文件访问(定位，写) 7AqbfLO
package NetFox; z5D*UOy5M
import java.io.*; $"}[\>e*{
e2>AL
*.VNyay
public class FileAccessI implements Serializable{ `Tk~?aY
-i_XP]b&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jLY$P<u?%P
RandomAccessFile oSavedFile; f)V6VNW.3
long nPos; d+5v[x~'
$" =3e]<
ka{!' ^
public FileAccessI() throws IOException Mhb~wDQl
{ k9NHdi7&2
this("",0); [r9HYju=
} : w>R|]
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L)S V?FBx
public FileAccessI(String sName,long nPos) throws IOException -6X+:r`>u
{ zz<o4bR
oSavedFile = new RandomAccessFile(sName,"rw"); T-x9IoE
this.nPos = nPos; l1 _"9a%H
oSavedFile.seek(nPos); ux17q>G
} T[g(S0dz
DK'S4%;Sp
\C2HeA\#SW
public synchronized int write(byte[] b,int nStart,int nLen) CHjm7
{ ,w=u?
int n = -1; 6\VZ6oS
try{ A6E~GJa
oSavedFile.write(b,nStart,nLen); -D1A
n = nLen; JL<<EPC
} nU6UjC|3
catch(IOException e) 8%a ^j\L
{ zyt >(A1
e.printStackTrace (); oh9L2"
} 5yj6MaqJ
.ezZ+@LI+#
_fHj8- s/
return n; ;E!] /oY<
} ER}5`*X{
%WX^']p
Id>I.e4
} Kw:%B|B<T
/1bQ RI^\
5Q8s{WQ
/* )t:8;;W@Ir
**SiteInfoBean.java 2r]o>X
*/ :2XX~|
package NetFox; sv#b5,>9
WD*z..`
WY5HmNX3E
public class SiteInfoBean { 6uk}4bdvq
TQ%F\@"
*<h)q)HS
private String sSiteURL; //Site's URL ~~m(CJ4S
private String sFilePath; //Saved File's Path =8"xQ>D62
private String sFileName; //Saved File's Name ~0}d=d5g
private int nSplitter; //Count of Splited Downloading File ^7t1'A8e<
*/|<5X;xIA
o!c~"
public SiteInfoBean() 'TA !JB+
{//nSplitter的缺省值为5 m6A\R KJ'
//default value of nSplitter is 5 6.[3N~pq
this("","","",5); ;hEeFJ=/G
} R+=wSG]
$'::51
CAN1~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nV8iYBBym
{ ,s:viXk
sSiteURL= sURL; _NpxV'E
sFilePath = sPath; U8,pe;/ln`
sFileName = sName; e+<9Sh7&
this.nSplitter = nSpiltter; 5ci1ce
s3K!~v\L]
'tjqfR
} k/BlkjlNE
lvLz){
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public String getSSiteURL() [| N73m,&
{ !\^W*nQ>l
return sSiteURL; dx$+,R~y
} CW.T`F
!;${2Q
ocZ^rqo2w
public void setSSiteURL(String value) [N<rPHT
{ +c__U Qx
sSiteURL = value; L@ejFXQg
} \Xr*1DI<
),^pi?
b&AeIU}&
public String getSFilePath() K}'?#a(aX=
{ ySF^^X$J
return sFilePath; }KEr@h,N
} y'non0P.
>Pvz5Hf/wW
;krIuk-
public void setSFilePath(String value) h R6Pj"@0
{ Ry?f; s
sFilePath = value; ~mv5{C
} N:Ir63X*#
P.mlk>r
Q^* 33
public String getSFileName() O]Yz7
{ \l`{u)V
return sFileName; bL+}n8B
} ofPv?_@
y! QYdf?
,R-aO= %
public void setSFileName(String value) P>03 DkbB
{ Py?Q::
sFileName = value; iJCv+p_f
} jvo^I$|2h
4U u`1gtz
2^f7GP
public int getNSplitter() )CgH|z:=b
{ imKMPO=
return nSplitter; QV4FA&f&
} 4=N(@mS
Yb1Q6[!
a>Zp?*9
public void setNSplitter(int nCount) sk AF6n
{ {i}E)Np
nSplitter = nCount; bfy=
} !/=.~B
} zJ@^Bw;A^@
ntW1 )H'o
Pw5[X5.DX
/* QZ*gR#K]Sz
**Utility.java [ugr<[6
*/ MV07RjeS
package NetFox; -=ZDfM
q;7DH4;t
}]JHY P\
public class Utility { aM(x--UR=
\xQu*M:!
7:<A_OLi
public Utility() +oL@pp0
{ \1QY=}
G.PRPl
'K#ndCGJ$
} %joL}f[
<Y$( lszT
//线程睡眠 )V&hS5P=S
public static void sleep(int nSecond) 4yjIR?
{ \k^ojzJ
try{ 8 VhU)fY
Thread.sleep(nSecond); g!9|1z
} l[rK)PM
catch(Exception e) h[Uo6`
{ <1 ;pyw y
e.printStackTrace (); e+MQmWA'F
} yrd1J$
} vTTXeS-b
<XN=v!2;
//日志 NCl@C$W9q
public static void log(String sMsg) d`~~Ww1
{ Q|e-)FS)
System.err.println(sMsg); 90K&oof?M
} UM<s#t`\3
^)(tO$S
w4M;e;8m[U
public static void log(int sMsg) p<,`l)o}~
{ TwI'XMO;A
System.err.println(sMsg); qI${7
} JYv<QsD
} PTqia!
_ElG&hyp
]hoq!:>M1
/* k+vfZ9bD(J
**TestMethod.java m/ID3_
*/ k[,0kP;
package NetFox; VqxK5
}r!hm?e
3dSC`K
public class TestMethod { _uXb>V*8
J_.cC
b&dv("e 4
public TestMethod() KHgn
{ ///xx/weblogic60b2_win.exe d ez4g
try{ P,9Pn)M|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D/GE-lq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '4Fwh]Ee
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8/&4l,M5
fileFetch.start(); >?rMMR+A
} F=e-jKogK
catch(Exception e){e.printStackTrace ();} v+8Ybq
K1Uq`TJ
L(sT/
} /,UnT(/k(
P.QF9%
~QDM .5
public static void main(String[] args) C+[)^2M{
{ aB?usVoS
new TestMethod(); aT(_c/t.
} Rn]xxa'
} +jyGRSo
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