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)); q)Uh_l.Cj
} [`'[)B
for(int i=0;i<nEndPos.length-1;i++) $&>z`bAS>
{ p=-:Z?EW1
nEndPos = nStartPos[i+1]; K@DK4{
} gr%!<2w
nEndPos[nEndPos.length-1] = nFileLength; 0 jszZ_
} O5;$cP:
} ,cg%t9
CG -^}xE:
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//启动子线程 ejID5NqG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nWd]P\a'V
for(int i=0;i<nStartPos.length;i++) a*fUMhIi
{ TGe)%jZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OB&lq.r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \4B2%H
nStartPos,nEndPos,i); JC[G5$E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); spVE'"^
fileSplitterFetch.start(); fQtV-\Bc
} _r6aLm2n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8&0+Az"{O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $cUTe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X=Th
nEndPos = " + nFileLength); 'Itsu~fza
// fileSplitterFetch[nPos.length-1].start(); 6,D)o/_
:vqfWK6mv
q_sQC5:s
//等待子线程结束 pO~lVM
//int count = 0; HS% P
//是否结束while循环 k8~/lE.Wy
boolean breakWhile = false; [kjmEMF9i
SW^/\cJ^
.@(+.G
while(!bStop) @\_l%/z{
{ :mpR}.^hv
write_nPos(); .^Z^L F
Utility.sleep(500); !x, ;&
breakWhile = true; /<\B8^yQ
tCw.wDq3=
6N^sUc0s
for(int i=0;i<nStartPos.length;i++) Gxj3/&]^Y
{ 13X0LN
if(!fileSplitterFetch.bDownOver) 3Xun>ZQ-
{ s?j` _B
breakWhile = false; C6-71`C0
break; .%iJin"
} ~qk5Mk4$
} ~gjREl,+D#
if(breakWhile) H /kSFf{
break; T==(Pw7R7
5,pKv
Ai 9UB=[R
//count++; 6jGPmOM/
//if(count>4) %kcyE<c
// siteStop(); D)u 9Y
} >*5+{~k~4
RH+'"f
r-ldqj
System.err.println("文件下载结束！"); H,F/u&O
} 0%9Nf!j
catch(Exception e){e.printStackTrace ();} mM&*_#( 6
} _B5t)7I
x9c/;Q&m
:Y{aa1
//获得文件长度 $h({x~Oj9
public long getFileSize() N0D)d
{ :-I~-Yj
int nFileLength = -1; vWM3JH~a6
try{ FzDZ<dJ
URL url = new URL(siteInfoBean.getSSiteURL()); *i}Nb*Z3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8, >YB+Hb
httpConnection.setRequestProperty("User-Agent","NetFox"); z&"-%l.b@}
(Nky?*
+:s]>R eDa
int responseCode=httpConnection.getResponseCode(); q $Hg\ {c
if(responseCode>=400) XuQ7nlbnq
{ |+^-b}0
processErrorCode(responseCode); fCA/
return -2; //-2 represent access is error xKKR'v:o\
} T%%+v#+
:OF:(,J
qrFC4\q}
String sHeader; g' xR$6t
V ifQ@
/<HEcB
for(int i=1;;i++) 2hjR'6h"Y
{ 1D,$Az~.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^Ms)T3dM
//Utility.log(in.readLine()); :uAW
sHeader=httpConnection.getHeaderFieldKey(i); NW.<v /?=,
if(sHeader!=null) p8>.Q/4
{ ?D].Za^km
if(sHeader.equals("Content-Length")) Pgy&/-u
{ MZ(TST"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q+MV@8w
break; g[rxKn\Z
} 'wo[iNy[
} a:PS}_.
else kp4*|$]
break; X[frL)k]
} uc% &g
} f PoC yl
catch(IOException e){e.printStackTrace ();} 0/8rYBV
catch(Exception e){e.printStackTrace ();} kKFSCl/g
b6IYo!3
]7QRelMiz+
Utility.log(nFileLength); B%v2)+?@
X(-e-:B4;
.b4_O CGg
return nFileLength; 9.KOrg5}L
} [e2sUO0~r
cT8`l!RD<
qsB,yckml
//保存下载信息（文件指针位置） -%&_LE9ZtS
private void write_nPos() 2V}tDN7c
{ q;T3bxp+
try{ ?fog 34g
output = new DataOutputStream(new FileOutputStream(tmpFile)); idwiM|.iU
output.writeInt(nStartPos.length); Xd_86q8o
for(int i=0;i<nStartPos.length;i++) @j%r6N
{ \dyJ=tg
// output.writeLong(nPos); oKIry 8'^N
output.writeLong(fileSplitterFetch.nStartPos); _}X_^taTZS
output.writeLong(fileSplitterFetch.nEndPos); n7RswX
} `?Pk~7
output.close(); ;79X#hI
} Wgl7)Xk.)
catch(IOException e){e.printStackTrace ();} SR9Cl
catch(Exception e){e.printStackTrace ();} i$)`U]
} KzRw)P
[sC]<2 r
5!ll #/ {`
//读取保存的下载信息（文件指针位置） /B$"fxFf
private void read_nPos() D6iHkDTg
{ ti:qOSIDTA
try{ Hno:"k?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :X>%6Xj?RV
int nCount = input.readInt(); (+<SR5,/3
nStartPos = new long[nCount]; |Ire#0Nwx
nEndPos = new long[nCount]; Do7&OBI~
for(int i=0;i<nStartPos.length;i++) p @@TOS
{ G:FP9
nStartPos = input.readLong(); %nJ^0X_]
nEndPos = input.readLong(); t[B\'f!
} aU]A#g
input.close(); pYo]lO
} l`L}*Q- 5
catch(IOException e){e.printStackTrace ();} ]8(_{@/
catch(Exception e){e.printStackTrace ();} :)v4:&do
} V#?GDe}[
6!} @vp![
OO@ (lt
private void processErrorCode(int nErrorCode) =,0E]MZ
{ QN_Zd@K*A
System.err.println("Error Code : " + nErrorCode); Zx(VwB2
} Egv (n@1
8LP L4l
hKw4[wB]
//停止文件下载 ;BV1E|j
public void siteStop() 4P@Ak7iL(V
{ a3i4eGT-
bStop = true; M,Q(7z?#5
for(int i=0;i<nStartPos.length;i++) .__X-+^
fileSplitterFetch.splitterStop(); OWsK>egD
?5e:w?&g@
2f1WT g)
} $m`?x5rL8
} ql5NSQ>{
//负责部分文件的抓取 "d'D:>z]%
**FileSplitterFetch.java sQrP,:=r#
*/ 'rJkxU{
package NetFox; A4.Q\0
dxkq*
jnvi_Rodm
import java.io.*; vn@9Sqk
import java.net.*; cq`v8
B&&:A4
w66iLQ\@
public class FileSplitterFetch extends Thread { @b\/\\{
$:V'+s4o
[z$th
String sURL; //File URL 42aYM!
long nStartPos; //File Snippet Start Position 9L;fT5Tp7
long nEndPos; //File Snippet End Position y^:!]-+
int nThreadID; //Thread's ID WpE\N0Yg
boolean bDownOver = false; //Downing is over (J8(_MF
boolean bStop = false; //Stop identical 7A|n*'[T>
FileAccessI fileAccessI = null; //File Access interface PSz|I8 c
/t`s.!k
dieGLA<5_X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lz.ta!6
{ MXsSF|-
this.sURL = sURL; 0R&$P6
this.nStartPos = nStart; b f.__3{
this.nEndPos = nEnd; 5LU8QHj3
nThreadID = id; d^sS{m\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~aKxwH
} ?sV0T)uk
)IQa]A
)%lPa|7s
public void run() [V_Z9-f*
{ 4(>|f_$
while(nStartPos < nEndPos && !bStop) K^j7T[pR
{ %EA|2O.D
s(W]>Ib
A L|F Bd
try{ ?4Z`^uy
URL url = new URL(sURL); Su99A.w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); coq7La[
httpConnection.setRequestProperty("User-Agent","NetFox"); ?yop#tjCbY
String sProperty = "bytes="+nStartPos+"-"; !, Y1FC
httpConnection.setRequestProperty("RANGE",sProperty); fB+4mEG@
Utility.log(sProperty); $8gj}0}eH
<&:OSd:%
v0)I rO
InputStream input = httpConnection.getInputStream(); };"-6e/9
//logResponseHead(httpConnection); -J8&!S8X
!t/I j~o
f QSP]?
byte[] b = new byte[1024]; R{"Kh2q_
int nRead; 33dHTV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BH"f\oc
{ wlk{V
nStartPos += fileAccessI.write(b,0,nRead); mm(Ff>O
//if(nThreadID == 1) ^6R?UG;6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?-w<H!Y7
} UfcQFT{()
F}p)Q$0
M:6Yy@#T.
Utility.log("Thread " + nThreadID + " is over!"); tQ=P.14>:
bDownOver = true; P%MYr"<$E
//nPos = fileAccessI.write (b,0,nRead); JGl0 (i*|
} ^ Q]I)U
catch(Exception e){e.printStackTrace ();} W8{g<. /
} z\wY3pIr2
} EM9K^l`
wp7<0PP
)Y.H*ca
//打印回应的头信息 [w&B>z=g$
public void logResponseHead(HttpURLConnection con) .} al s
{ +?r,Nn
for(int i=1;;i++) PhTMXv<cE
{ #[$^M:X.
String header=con.getHeaderFieldKey(i); 5Fa.X|R~
if(header!=null) Fq\vFt|m<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S"+X+Oxp7?
Utility.log(header+" : "+con.getHeaderField(header)); Yxik.S+G
else 2wR?ON=Q
break; 5=Cea
} )5n*4A
} V0 70oZ
BN??3F8C
s6=jHrdvv
public void splitterStop() GH ]c
{ [t#xX59
bStop = true; G`1!SEae
} 66ULR&D8
PM]|S`
fCC^hB]'
} RLl*@SEi"
Eod'Esye5
JmlMfMpXMs
/* b]A9$-
**FileAccess.java pjG/`
*//文件访问(定位，写) .8[*`%K>
package NetFox; p1}umDb%
import java.io.*; FFC"rG
{\:"OcP #
Q`= ,&;T>
public class FileAccessI implements Serializable{ _#;UXAi
ZQ@Ul
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ::<v; `l
RandomAccessFile oSavedFile; 3UXaA;
long nPos; b{ M'aV
M%{,?a0V
.|?UqZ(,
public FileAccessI() throws IOException Cpg>5N~;L
{ <rQ+ErDA
this("",0); =[_=y=G
} o57r ,`N
/+ yIcE(&3
8%\0v?a5
public FileAccessI(String sName,long nPos) throws IOException Sm5T/&z
{ vyS8yJUY
oSavedFile = new RandomAccessFile(sName,"rw"); .#Vup{.
this.nPos = nPos; Al}D~6MD
oSavedFile.seek(nPos); Sv#S_jh
} b=$(`y
lEXER^6
Mp-hNO}.Z
public synchronized int write(byte[] b,int nStart,int nLen) Q0j4c
{ Crg@05Z
int n = -1; vRI0fDu
try{ !pJd^|4A]
oSavedFile.write(b,nStart,nLen); ?"@`SEdnU2
n = nLen; ]=Tle&yM+T
} aGz$A15#
catch(IOException e) tS[@3h
{ |#i|BVnoE
e.printStackTrace (); <>71;%e;'
} +eUWf{(_
Bx" eX>A8
(qyT,K8
return n; u%24% Q
} DnP "7}v
HSG7jC'_
wdMVy=SS
} ehTRw8"R
goje4;
gt \O
/* wg}rMJoG|
**SiteInfoBean.java 4 Q<c I2|
*/ wAA9M4
package NetFox; is6M{K3
JqTR4[`Z\
Dkyw3*LCn%
public class SiteInfoBean { :k/Z|
-Cc2|~n
:ceT8-PBRx
private String sSiteURL; //Site's URL Va-.
private String sFilePath; //Saved File's Path 1e)5D& njS
private String sFileName; //Saved File's Name `:*O8h~i^8
private int nSplitter; //Count of Splited Downloading File ?#0m[k&`
3uy^o
W*WSjuFr2
public SiteInfoBean() J#) %{k_
{//nSplitter的缺省值为5 h8 !(WO!
//default value of nSplitter is 5 ^3O`8o
this("","","",5); i5;_
} $ISx0l~
_t-e.2a v
N2.(0 G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) spG3"Eodi
{ [kKg?I$D@B
sSiteURL= sURL; H[[#h=r0f
sFilePath = sPath; I7]qTS[vg
sFileName = sName; 2qDyb]9
this.nSplitter = nSpiltter; bH`r=@.:cu
Q&`if O
Vg^,Ky,
} 1zGhX]z
m#|h22^H
/VHQ!Wi
public String getSSiteURL() OhiY <
{ S]g`Ds<
return sSiteURL; 9Ac4'L
} bFB.hkTP
g$T% C?
e\95X{_'
public void setSSiteURL(String value) zW:r7 P.
{ \H{UJ
sSiteURL = value; $Ma*qEB
} KYM%U"jD
A|<i7QVY
/#Lm)-%G
public String getSFilePath() Sej(jJX1
{ ^X|Bzz)
return sFilePath; &'"dYZj{
} ZRn!z`.0
PL*1-t?#
i:n1Di1~E
public void setSFilePath(String value) jpt-5@5O
{ u!TMt8+c
sFilePath = value; ;.I,R NM
} lnWscb3t
=y]FcxF
a"!r]=r
public String getSFileName() +L-(Lz[p
{ !)HB+yr
return sFileName; W.7XShwd*2
} il~A(`+YO
Jl-:@[;
,r,$x4*
public void setSFileName(String value) LB/1To
{ 8],tGMu
sFileName = value; q{2 +Inf#:
} -`ss7j&b3
Co^GsUJ
0I7 r{T
public int getNSplitter() -:|t^RM;FT
{ I`uOsZBO/
return nSplitter; _5H0<%\
} UE 1tm
!~-@p?kW/
4%>2>5
public void setNSplitter(int nCount) DgGG*OXY
{ EeDK ^W8N
nSplitter = nCount; gT#hF]c:
} ;G4g;YHy|
} f19'IH$n{
x.ucsb
w'&QNm>
/* Q+zy\T
**Utility.java VskdC?yIp
*/ ~!#2s'
package NetFox; Lem:zXj
?vg|;Q
gh<2i\})'
public class Utility { d#u*NwY}
]^v*2!_(
t$(<9
public Utility() QRz5eGpW
{ w3K>IDWI7
+OfHa\Nz
#OVS]Asn}
} YjzGF=g#
[KNA5(Y0
//线程睡眠 SxW.dT8{
public static void sleep(int nSecond) VL/KC-6
{ Xr]<v%,C
try{ p{w:^l(
Thread.sleep(nSecond); E#(dri*#t
} U@"f(YL+"
catch(Exception e) ANlzF&K
{ !d{Ijs'T
e.printStackTrace (); VPUm4%?p$
} FV5~sy
} RFT`r
N&]_U%#Q
//日志 ]Nb~-)t%B
public static void log(String sMsg) 2A(IsUtqO:
{ DNGj81'c
System.err.println(sMsg); x?n13C
} +W^$my)<
+.IncY8C$
@9\L|O'~?
public static void log(int sMsg) f6JC>Np
{ k'PNfx\K
System.err.println(sMsg); `c/mmS
} ?.6fVSa
} o>@9[F,h+
U%l<48@8
gbjql+Mx+
/* {:ZsUnzm
**TestMethod.java /<)kI(gf
*/ aJSBG|IC
package NetFox; 9 M!U@>
K%3{a=1
<iNxtD0
public class TestMethod { \) vI-
/tu\q
{]3Rk
public TestMethod() ~s-"u *>
{ ///xx/weblogic60b2_win.exe IpKpj"eoLy
try{ Oi,:q&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lvk r2Meu<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fe+2U|y
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7R=A]@
fileFetch.start(); ?f4jqF~Fh
} G\/7V L
catch(Exception e){e.printStackTrace ();} MRa |<yK
*Fm#Qek
YHfk; FI
} 3mH(@-OA
U_ *K%h\m
_aK4[*jnqh
public static void main(String[] args) >;Vy{bL8
{ y({EF~w
new TestMethod(); |>jlmaV
} k8O%gO
} C252E
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