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)); 7q9gngT1LA
} o5Rz%k#h
for(int i=0;i<nEndPos.length-1;i++) E^ h=!RW{
{ 5iFV;W
nEndPos = nStartPos[i+1]; Vs0 SXj
} cJ}QXuuUv
nEndPos[nEndPos.length-1] = nFileLength; %NHYW\sKX
} QYE7p\
} 6a}r( yP
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%.x@gi q
//启动子线程 17UK1Jx,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (hZ:X)E>
for(int i=0;i<nStartPos.length;i++) GaNq2G
{ F#q&(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _ptP[SV^j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :pKG\A
nStartPos,nEndPos,i); ?p8Qx\%*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |DG@ht
fileSplitterFetch.start(); &,W$-[
} z)L}ECZh9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +$beo2x6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E)'8U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s^|\9%WD
nEndPos = " + nFileLength); p%RUHN3G[
// fileSplitterFetch[nPos.length-1].start(); R ZcH+?7
jqoPLbxT
saK;[&I*
//等待子线程结束 u35q,u=I
//int count = 0; ]O{_O&w
//是否结束while循环 !;}2F-
boolean breakWhile = false; w6,*9(;$Pk
,?b78_,2
ua& @GXvZ
while(!bStop) Sb<\-O14"
{ LcUlc)YH5
write_nPos(); u(vw|nj`
Utility.sleep(500); (wL3 +
breakWhile = true; i!~>\r\6\
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T^)plWw
for(int i=0;i<nStartPos.length;i++) (Pz8iz
{ lBiovT
if(!fileSplitterFetch.bDownOver) XJFnih
{ t"YIq/08
breakWhile = false; ~/c5hyTx
break; %Dyh:h
} mU]s7` %<>
} [ -12]3
if(breakWhile) 'O "kt T
break; i_Ar<9a~
u5E/m
9t}xXk
//count++; YC)hX'A\
//if(count>4) )5i*/I\
// siteStop(); Jk*QcEE=
} u9}!Gq
C"No5r'K3
N9*UMVU
System.err.println("文件下载结束！"); `E;)`J8b
} W?PWJkIw
catch(Exception e){e.printStackTrace ();} .;Z.F7{q
} !rHx}n{rw
[tN` :}?
.\4l'THn,0
//获得文件长度 *.dKR
public long getFileSize() S-P{/;c@
{ R9E6uz.j
int nFileLength = -1; R\ q):,
try{ FG _,
URL url = new URL(siteInfoBean.getSSiteURL()); d"l}Ny)C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g 2#F_
httpConnection.setRequestProperty("User-Agent","NetFox"); 4g'}h`kh
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int responseCode=httpConnection.getResponseCode(); 7uA\&/ ,
if(responseCode>=400) N4+g("
{ KE#$+,?
processErrorCode(responseCode); TRCI\
return -2; //-2 represent access is error cS 4T\{B;
} kpWzMd &RK
2b~ HHVruX
"_oLe;?$c
String sHeader; U[Nosh)hu\
m/" J s
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for(int i=1;;i++) ip674'bq7R
{ \@:j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }2mI*"%)\u
//Utility.log(in.readLine()); L3g9b53\
sHeader=httpConnection.getHeaderFieldKey(i); ,-!2 5G
if(sHeader!=null) 1zR/HT
{ ^K/G5
if(sHeader.equals("Content-Length")) AW62~*
{ ~Q_F~0y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <\Vi,,
break; z2ds8-z
} 0ovZ&l
} CY5w$E
else -2z,cj&E{
break; @,GjeF]!
} z=[l.Af_
} ^}tLnF
catch(IOException e){e.printStackTrace ();} 4^`PiRGt
catch(Exception e){e.printStackTrace ();} "W3W:vl!
9Dy)nm^
jB`7T^bU
Utility.log(nFileLength); t+jIHo
([1=>Jw"
<TL])@da
return nFileLength; kO jEY
} {GAsFnZk
eC.w?(RB
C1n??Y[
//保存下载信息（文件指针位置） J/L)3y
private void write_nPos() n}42'9p
{ 6(,ItMbI
try{ P`z7@9*j
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9A(n_Rs7?
output.writeInt(nStartPos.length); n}+wd9J*!2
for(int i=0;i<nStartPos.length;i++) l<s :%%CX
{ ]}_p3W "Y9
// output.writeLong(nPos); JXlTN[O
output.writeLong(fileSplitterFetch.nStartPos); j-j'phK
output.writeLong(fileSplitterFetch.nEndPos); *>G^!e.u
} |G>q:]+AV
output.close(); 4$..r4@
} mf+K{y,L
catch(IOException e){e.printStackTrace ();} tP&{ J^G
catch(Exception e){e.printStackTrace ();} md.*
} )~1.<((<
"$# $f
Ml'bZLwq
//读取保存的下载信息（文件指针位置） ?Ozk^#H[
private void read_nPos() jM{qRfOrg
{ [^h/(a`
try{ @ysJt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3S;>ki4(0
int nCount = input.readInt(); 2=i+L z^
nStartPos = new long[nCount]; ,oC={^l{
nEndPos = new long[nCount]; niXHK$@5
for(int i=0;i<nStartPos.length;i++) ?aP1
{ Rc$=+K#
nStartPos = input.readLong(); '2;Ny23
nEndPos = input.readLong(); Ej-=y2j{g
} ,)0/Ec
input.close(); ?,.HA@T%
} ]H@v
catch(IOException e){e.printStackTrace ();} BnY\FQ)K
catch(Exception e){e.printStackTrace ();} AaJ,=eQ
} N:m@D][/sW
A}az m>
BiVd ka
private void processErrorCode(int nErrorCode) z:0-aDeM
{ 2<`gs(oxXe
System.err.println("Error Code : " + nErrorCode); iKP\/LR<n
} "~.8eKRQ
g?k#wj1uH
S-H-tFy\\
//停止文件下载 4WBoZJ
public void siteStop() Om&{4a\
{ d;@E~~o?B]
bStop = true; NgDZ4&L
for(int i=0;i<nStartPos.length;i++) j TB<E=WC
fileSplitterFetch.splitterStop(); e<: 4czh8
,"v)vTt
9-X{x95]
} 6KBzlj0T+
} 1{;[q3a
//负责部分文件的抓取 p@!@^1j=
**FileSplitterFetch.java >*<6 zQf
*/ f4A4
package NetFox; KoxGxHz^Y3
UH1S_:6
q9g[+*9]$
import java.io.*; RGx]DP$5G
import java.net.*; }uV?
L*SSv wSL
2Be?5+
public class FileSplitterFetch extends Thread { YokZar2a0
GDNh?R
Bsih<`KF^
String sURL; //File URL T9U2j-lA?
long nStartPos; //File Snippet Start Position ]iE.fQ?;J
long nEndPos; //File Snippet End Position lN][xnP
int nThreadID; //Thread's ID _taHf %\4
boolean bDownOver = false; //Downing is over ib""Fv7{
boolean bStop = false; //Stop identical &?5{z\;1"
FileAccessI fileAccessI = null; //File Access interface f2SU5e2
u]>>B>KOJ7
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b[&,%Sm+6
{ ,:dEEL+>c
this.sURL = sURL; ^!v}
this.nStartPos = nStart; iz%A0Z+`bg
this.nEndPos = nEnd; Te U7W?M^
nThreadID = id; w$U/;C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4,*^QK
} 7S~9E2N
=p&'_a^$
_:fO)gs|1
public void run() #.<F5
{ mC[U)` ey
while(nStartPos < nEndPos && !bStop) 9Sj:nn^/u
{ w?$u!X
z kX-"}$8
]ZryY EB
try{ ]zwqGA
URL url = new URL(sURL); rO?x/{;ai
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "<jEI /
httpConnection.setRequestProperty("User-Agent","NetFox"); ~b6<uRnM.
String sProperty = "bytes="+nStartPos+"-"; a@_Cx
httpConnection.setRequestProperty("RANGE",sProperty); Mn }Z9S[
Utility.log(sProperty); yzM+28}L<I
gt t$O
)T};Q:
InputStream input = httpConnection.getInputStream(); eDM0417O(
//logResponseHead(httpConnection); >%p m"+h{
>*t>U8
kj3o1Y
byte[] b = new byte[1024]; )`+@j.75
int nRead; /4B4IT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I\uB"Z{9
{ 6 XOu~+7
nStartPos += fileAccessI.write(b,0,nRead); g=YiR/O1QN
//if(nThreadID == 1) +S5_J&~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YT(1 "{:
} P7k$^n
C}P \kDM
=@jMx^A"
Utility.log("Thread " + nThreadID + " is over!"); F)5B[.ce
bDownOver = true; ,pa&he
//nPos = fileAccessI.write (b,0,nRead); QH' [(
} JJHvj=9'o
catch(Exception e){e.printStackTrace ();} $H:h(ia:
} ! 7*_Z=
} .kKwdqO+zB
yDyeP{
hHl-;%#
//打印回应的头信息 dbUZGn~
public void logResponseHead(HttpURLConnection con) 6u, 0y$3
{ ^'I5]cRa
for(int i=1;;i++) !4,xQ^
{ ic]tUOC:
String header=con.getHeaderFieldKey(i); (F '
if(header!=null) T!xy^n]}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ce'2lo
Utility.log(header+" : "+con.getHeaderField(header)); 8!%"/*P$
else j _9<=Vu
break; P~ pbx
} [O+^eE6h
} yqb<<4I
zcWxyLifl0
7RFkHME
public void splitterStop() Qp{-!*
{ Ww tQ>'R"
bStop = true; YB3=ij!K
} >;r05,mc
$z,DcO.vz
cASHgm
} <$6'Mzf
{5IG3'
u&_U CJCf
/* EM w(%}8w
**FileAccess.java 'CO[s.03
*//文件访问(定位，写) LqsJHG
package NetFox; sfPN\^k2
import java.io.*; Jb.u^3R@
1`_)%Y[ZJ
4bzn^
public class FileAccessI implements Serializable{ Bg0cC
vl~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hf{%N'4
RandomAccessFile oSavedFile; 4^ 6L])y
long nPos; }/r%~cZ
sLqvDH?V
B]F7t4Y!
public FileAccessI() throws IOException *9(1:N;#
{ X3O$Sd(D
this("",0); W*`6ero
} ld?.o/
`#8R+c=$
rg/vxTl
public FileAccessI(String sName,long nPos) throws IOException ~RAH -]
{ H^:|`T|,
oSavedFile = new RandomAccessFile(sName,"rw"); 8vW`E_n
this.nPos = nPos; 2B dr#qr
oSavedFile.seek(nPos); $-fY8V3[
} r$Qh`[<
BQ0\+
_N';`wjDY
public synchronized int write(byte[] b,int nStart,int nLen) -Ep6.v
{ }c5`~ LLK
int n = -1; :]QxT8B
try{ q#3X*!)
oSavedFile.write(b,nStart,nLen); g^UWf<xp
n = nLen; h18y?e7MU
} T["(YFCByg
catch(IOException e) fEv36xb2S
{ D~&e.y/gHN
e.printStackTrace (); _u2
} JhIK$Ti
*S_Iza #&x
0*@S-Lj^c
return n; Lo9?,^S
} M[_I16s
)6+W6:
3y,?>-
} mP[u[|]
@{lnfOESl
$7d"9s\$"
/* 6E]rxps}"
**SiteInfoBean.java %WN2 xCSf
*/ #?6RoFgMe
package NetFox; 0+pJv0u
h cXqg
c iX2G
public class SiteInfoBean { .y+U7"?s*
]]3D` F}
+KNr1rG
private String sSiteURL; //Site's URL \]%U?`A
private String sFilePath; //Saved File's Path ?9TogW>W
private String sFileName; //Saved File's Name OhEL9"\<
private int nSplitter; //Count of Splited Downloading File 0{F.DDiNT
>.\E'e5^C
UI;{3Bn
public SiteInfoBean() S &u94hlC
{//nSplitter的缺省值为5 m@~x*+Iz
//default value of nSplitter is 5 g"Bv!9*H
this("","","",5); n]Y _C^
} 1[^d8!U
yk2j&}M
q3`t0eLZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e_V(G
{ y{JkY\g
sSiteURL= sURL; ;zDc0qpw
sFilePath = sPath; Xk'.t|
sFileName = sName; {IWb:p#I]
this.nSplitter = nSpiltter; K>y+3HN[6
.~J^`/o
{wI0 =U
} Lt_]3go
's<}@-]
S}X:LHr*
public String getSSiteURL() BL67sva;
{ fF%r$`2
return sSiteURL; 'oG'`ED"
} O5 SX"A
1~Nz6
:%{7Q$Xv<
public void setSSiteURL(String value) 1zRO==b
{ 7~'@m(9e
sSiteURL = value; 9[Mu
} u2QJDLMJv
xh0!H| R
K4BMa]/U
public String getSFilePath() bX,Z<BvbF
{ 5 *_#"
return sFilePath; ']Z8C)tK
} \#slZ;&s
rQJoaP+\q
lxZXz JkqZ
public void setSFilePath(String value) J$0*K+m
{ w]_a0{Uh
sFilePath = value; @ 55Y2
} O);V{1P
bGZy0.
X`&E,;bIb
public String getSFileName() Y%3j>_\;
{ \;}dSSB1
return sFileName; PyYe>a;.
} -UO$$)Q
v!2`hqO
^IpS 3y
public void setSFileName(String value) 7DDot_qb
{ 4"{q|~&=:$
sFileName = value; Ab`Gb
} gIeo7>u
_wIAr
3XIxuQwf
public int getNSplitter() /=%4gWtr
{ ||qW'kNWM
return nSplitter; }U9e#>ex
} IcB>Hg5
V%))%?3x_
52oR^|
public void setNSplitter(int nCount) E)Dik`Ccl
{ @Z)&3ss
nSplitter = nCount; ^-DK<jZ^
} "xWC49
} =Oy,SX
fYwumx`J
p?Y1^/
/* t^q/'9Ai&J
**Utility.java *{uu_O
*/ /SyiJCx0
package NetFox; h<?Vzl
1UOFTI2S|
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public class Utility { {2!.3<#
'SC`->F4D
xMe[/7)4
public Utility() '{),gV.
{ 1_A< nt?'R
nF=h|rN
iKu5K0x{>I
} E]bjI$j
rKO[;]_*
//线程睡眠 xSw ^v6!2
public static void sleep(int nSecond) DwoO([&I
{ $N~8^6
try{ ;#AV~Y- s
Thread.sleep(nSecond); <MoWS9s!yb
} lE4.O
catch(Exception e) By" =]|Q
{ Kpg]b"9.R
e.printStackTrace (); v=!]t=P)t
} vFQ'sd]C
} Nx~8]h1(
>xT8[
//日志 <J\z6+,4E
public static void log(String sMsg) `w2hJP
{ nT:ZSJWM
System.err.println(sMsg); WUKYwA/t
} $cnIsyKWY
geua8;
@`)A)
public static void log(int sMsg) 4\>Cnc{
{ ]"^U
System.err.println(sMsg); c{zQX0
} 7&E3d P
} +[ !K
OT+LQ TE
Dr&2qX!
/* tv5G']vO\
**TestMethod.java h>9GfF3
*/ }!x\qpA
package NetFox; h49|x&03
Bi9 S1p
Ab/gY$l
public class TestMethod { 6|L<? X
NZ7g}+GTG
xM'bb5
public TestMethod() CtfI&rb[
{ ///xx/weblogic60b2_win.exe P-.>vi^+
try{ o[X'We;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HTAJn_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2Gd.B/L6
SiteFileFetch fileFetch = new SiteFileFetch(bean); `{#0C-
fileFetch.start(); )l~:Puvh
} _SY4Qs`d
catch(Exception e){e.printStackTrace ();} A}W)La\
=Q>'?w>
},lHa!<^
} D6fry\
Bvb.N$G
7.`Fe g.
public static void main(String[] args) B&3oo
{ @z[,w`
new TestMethod(); cks53/Z
} 5[suwaJQ
} ssj(-\5
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