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)); [7gz?9VyLF
} xW5`.^5
for(int i=0;i<nEndPos.length-1;i++) [m h>N$
{ `^hA&/1
nEndPos = nStartPos[i+1]; :.XlAQR~b
} ~,&8)1
nEndPos[nEndPos.length-1] = nFileLength; o4EY2
} S|k@D2k=
} 9ck"JMla
tugIOA
-bOtF%
//启动子线程 CkNR{?S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yx-"&K=`
for(int i=0;i<nStartPos.length;i++) :LNZC,-f}5
{ U2<q dknB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H+Bon=$cE!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =5B5
nStartPos,nEndPos,i); [#Gu?L_W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @#t<!-8d
fileSplitterFetch.start(); E=,5%>C0#%
} .`+~mQ Wn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sq_.RU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TsoxS/MI"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c|9g=DjK
nEndPos = " + nFileLength); sGtxqnX:J
// fileSplitterFetch[nPos.length-1].start(); <_|@~^u
?zutU w/m
*v K~t|z
//等待子线程结束 a BMV6'
//int count = 0; S$fS|N3]%
//是否结束while循环 jFe8s@7
boolean breakWhile = false; vvxD}p=y
Lv/}&'\(
u;rmqo1
while(!bStop) 5~DKx7P!Z
{ L3wj vq^
write_nPos(); ]oSx]R>{f
Utility.sleep(500); YQd($
breakWhile = true; fcF|m5
C za}cF
k`N*_/(|n
for(int i=0;i<nStartPos.length;i++) ">1wPq&
{ M*3G
if(!fileSplitterFetch.bDownOver) 8YRT0/V
{ WR#h~N 9c
breakWhile = false; 1<#D3CXK
break; gvo98Id
} NR_3nt^h
} GiuE\J9i
if(breakWhile) urx?p^c
break; O^-QqCZE
gTTKjlI[
:'ZR!w
//count++; 3-:^mRPJ
//if(count>4) t/O^7)%
// siteStop(); ?;P6#ByR
} pn(i18x
T>| hID
PP'5ANK
System.err.println("文件下载结束！"); ,=Wj*S)~
} H'YKj'
catch(Exception e){e.printStackTrace ();} %_Lz0L64k
} z$%8'
D60quEe3%
Eb9h9sjv
//获得文件长度 i{$P.i/&
public long getFileSize() H9TeMY
{ ",gVo\^
int nFileLength = -1; Z9 ws{8@_
try{ w)vpo/?
URL url = new URL(siteInfoBean.getSSiteURL()); vmkiw1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DU"Gz!X]Jd
httpConnection.setRequestProperty("User-Agent","NetFox"); U ^O4HJ
Hn)? xw]x
^J7q,tvbJ
int responseCode=httpConnection.getResponseCode(); ['\R4H!x
if(responseCode>=400) <BBzv-?D
{ +0ukLc@
processErrorCode(responseCode); .{8[o[w =
return -2; //-2 represent access is error Pz2Q]}(w
} ~gZ1*8s`
]JGq{I>%+6
jsgDJ}
String sHeader; ~s'}_5;VY
aDX&j2/
cyWb*Wv
for(int i=1;;i++) GR*sk#{
{ Hc\@{17
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [|*7"Q(
//Utility.log(in.readLine()); u?SwGXi~8
sHeader=httpConnection.getHeaderFieldKey(i); zJ8T.+qJ
if(sHeader!=null) dT7fyn
{ ~1*37w~
if(sHeader.equals("Content-Length")) |*zgX]-+;
{ #M w70@6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r]\[G6mE%
break; JiXE{(
} Fng
} -WyB2$!(
else Y+23 jlgb
break; ;2g.X(Ra
} sXPva@8_
} >ZPu$=[W
catch(IOException e){e.printStackTrace ();} [Nm?qY
catch(Exception e){e.printStackTrace ();} r 56~s5A
kkHK~(>G
[vb#W!M&|
Utility.log(nFileLength); y7#+VF`xf
k3B_M9>!
OzC%6;6h
return nFileLength; 85|u;Fxf
} b}Im>n!
1qn/*9W}=
X.#9[3U+
//保存下载信息（文件指针位置） _/P;`@
private void write_nPos() F)eP55C6
{ =m (u=|N3
try{ rBL2A
output = new DataOutputStream(new FileOutputStream(tmpFile)); kP('X/
output.writeInt(nStartPos.length); tuwlsBV
for(int i=0;i<nStartPos.length;i++) `:r-&QdU o
{ &DYC3*)Jih
// output.writeLong(nPos); '*`n"cC:
output.writeLong(fileSplitterFetch.nStartPos); pl,XS6mB
output.writeLong(fileSplitterFetch.nEndPos); j&S.k
} @Q ~;@M
output.close(); yG~Vvpv
} 7W4m&+
catch(IOException e){e.printStackTrace ();} $;ny`^8
catch(Exception e){e.printStackTrace ();} |p*cI @
} {*hGe_^
{y@8E>y5$
_hJ+8B^`
//读取保存的下载信息（文件指针位置） OC,yLQ
private void read_nPos() 94 6r#`q
{ e"sv_$*
try{ 6A>bm{`c:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vOKNBR2
int nCount = input.readInt(); uInI{>
nStartPos = new long[nCount]; (?,jnnub
nEndPos = new long[nCount]; A\7sP =
for(int i=0;i<nStartPos.length;i++) _f>)G3p
{ .@;5"
nStartPos = input.readLong(); d?YSVmG
nEndPos = input.readLong(); sLTQm*jL
} dQp>z%L)
input.close(); vzSjfv
} >^#Liwm
catch(IOException e){e.printStackTrace ();} YT[=o}jS
catch(Exception e){e.printStackTrace ();} ^oq|^O
} L?8OWLjRy
DTi^* Wj
vYLspZ;S
private void processErrorCode(int nErrorCode) ?AxB0d9z
{ 9'|k@i:
System.err.println("Error Code : " + nErrorCode); *&_A4)
} l&W:t9o
9w&CHg7D i
dW5r]D[Cx
//停止文件下载 u0?TMy.%
public void siteStop() >N`, 3;Z
{ 0%\fm W j
bStop = true; "[z/\l8O
for(int i=0;i<nStartPos.length;i++) 5?(dI9A"K
fileSplitterFetch.splitterStop(); v=dN$B5y3
q:jv9eL.O
I)*J,hs1
} =:R${F
} 6b` Jq>v
//负责部分文件的抓取 6+s&%io4
**FileSplitterFetch.java ++8 Xi1
*/ r}|)oG,=
package NetFox; 'f %oL/,
7uv"#mq
Pq-@waH3
import java.io.*; oz3!%'
import java.net.*; l% %cU"
7:$dl#
Ew{N2
public class FileSplitterFetch extends Thread { trLxg H_Y
}VH2G94Ll
w+\RSqz/
String sURL; //File URL ;U tEHvE*
long nStartPos; //File Snippet Start Position v=uQ8_0~N
long nEndPos; //File Snippet End Position X^m@*,[s
int nThreadID; //Thread's ID _m#TL60m
boolean bDownOver = false; //Downing is over L5&,sJz
boolean bStop = false; //Stop identical ">fRM=fl
FileAccessI fileAccessI = null; //File Access interface chuJj IY
@ K2Ncb7
/<O9^hA|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !#olG}#[
{ !+UXu]kA
this.sURL = sURL; eIPk$j{e
this.nStartPos = nStart; xAn|OSe
this.nEndPos = nEnd; ~7\`qH
nThreadID = id; )kKeA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &Dp&
} 9]{Ss$W3x
OWYY2&.h
dj6Lf
public void run() 4h}\Kl
{ IL*MB;0>
while(nStartPos < nEndPos && !bStop) J04R,B
{ 4dSAGLpp
6,R<8a;Wn
>Ij#+=
try{ `"iPJw14
URL url = new URL(sURL); qX[C%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +$^[r
httpConnection.setRequestProperty("User-Agent","NetFox"); jM'Fb.>~
String sProperty = "bytes="+nStartPos+"-"; D2:ShyYAS
httpConnection.setRequestProperty("RANGE",sProperty); %a-fxV[
Utility.log(sProperty); r"5\\qf5*
RC/&dB
4 T/ ~erc
InputStream input = httpConnection.getInputStream(); yN#]Q}4
//logResponseHead(httpConnection); AZJ|.mV q
]InDcE
,zBc-Cm
byte[] b = new byte[1024]; d _=44( -
int nRead; c8cGIAOY)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UyNP:q:
{ (i@(ZG]/
nStartPos += fileAccessI.write(b,0,nRead); t$Ua&w
//if(nThreadID == 1) Hu!<GB~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B=%YD"FAv
} N,cj[6;T%
_9/Af1X
<g8{LG0
Utility.log("Thread " + nThreadID + " is over!"); <S@2%%W
bDownOver = true; ;/^O7KM-
//nPos = fileAccessI.write (b,0,nRead); t{ridA}
} !6s]p%{V
catch(Exception e){e.printStackTrace ();} # kmI#W"^
} /q`f3OV"
} DEzL]1;P
fvDcE]_%H
BUsAEwM
//打印回应的头信息 J\I`#
public void logResponseHead(HttpURLConnection con) 8O*O5
{ 6 )Qe*S
for(int i=1;;i++) Ti5"a<R4m6
{ 3SOrM
String header=con.getHeaderFieldKey(i); x C>>K6Nb
if(header!=null) 00A2[gO9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vmtmiN8;d
Utility.log(header+" : "+con.getHeaderField(header)); bgmOX&`G
else |Gb~[6u
break; w:9n/[
} ^`(3X
} X*:)]p(R
c5HW.3"
LS1}j WU!
public void splitterStop() ?vP}#N!=d
{ e(-Vp7vXG
bStop = true; \88IFE
} @,q<][q
P-\T BS_O
}/.b@`Dh;
} Y{m1\s/o
rP&.`m88n
Z9PG7h
/* `ve5>aw0_Y
**FileAccess.java 4*+)D8
*//文件访问(定位，写) T(eNK c2
package NetFox; }nNCgH
import java.io.*; r6`KZ TU
,tOc+3Qz$
cz*Z/5XH
public class FileAccessI implements Serializable{ xV5eKV
@1 )][r-7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :U#4H;kk~j
RandomAccessFile oSavedFile; 0o&7l%Y/
long nPos; 0GiL(e|
@X0$X+]E*8
rIF6^?
public FileAccessI() throws IOException *ps")?tlC
{ 6rzXM`cs
this("",0); 9m_Hm')VG
} c ]&|.~2&
c5tCw3$t
Y-:{a1/RKo
public FileAccessI(String sName,long nPos) throws IOException X9n},}bJ"
{ cH\.-5NQ
oSavedFile = new RandomAccessFile(sName,"rw"); L[7Aa"R
this.nPos = nPos; u+vUv~4A6
oSavedFile.seek(nPos); IqmoWn3
} 0N*~"j;r#M
Yf,U2A\
Y+#VzIZw
public synchronized int write(byte[] b,int nStart,int nLen) _n_|skG
{ . [\S=K|/
int n = -1; GbZqLZ0
try{ pWXoJ0N
oSavedFile.write(b,nStart,nLen); aUX.4#|%
n = nLen; FOd)zU*L2
} =P<7tsSuoK
catch(IOException e) BDT1qiC
{ |Orp:e!
e.printStackTrace (); [CJr8Qn
} 41jx+ 0\Z
(Puag*
RI jz7ZG
return n; -XtDGNHF
} h48 jKL(
^iaG>rvA
qY$/i#
} G4eY}3F7,4
&'-ze,k}
t#6@~49
/* D^9r#&
**SiteInfoBean.java Y5Jrkr)k
*/ -*Z;EA-
package NetFox; ht%:e?@i
%JC-%TRWK
%$L!N-U6
public class SiteInfoBean { d@-bt s&3
xA>O4SD
h*9s^`9)
private String sSiteURL; //Site's URL H"A|Z6y$^
private String sFilePath; //Saved File's Path ?4,e?S6,[
private String sFileName; //Saved File's Name ZkZTCb`/l
private int nSplitter; //Count of Splited Downloading File UFy"hJchO
eE/E#W8
}<hyW9
public SiteInfoBean() (},TZ+u
{//nSplitter的缺省值为5 X!%CYmIRb
//default value of nSplitter is 5 4:p+C-gs
this("","","",5); |+Fko8-
} w8df-]r
L^zF@n^5A
w(KB=lA2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WS?"OTH.^\
{ Hjm
sSiteURL= sURL; MxO0#
sFilePath = sPath; E/</
sFileName = sName; VMZ"i1rP
this.nSplitter = nSpiltter; m:,S1V_jl
t Tky
S~mpXH@
} )ieT/0nt
W7QcDR y6
2Po e-=
public String getSSiteURL() " E U[Lb
{ 8f37o/L
return sSiteURL; |lOH PA
} ?UlAwxn
:NJ(QkTZv
xM3T7PV9
public void setSSiteURL(String value) 3~7X2}qU
{ 7]w]i5
sSiteURL = value; QVVR_1Q
} 2O^7zW
6WEYg
Qyr^\a;k'
public String getSFilePath() ersddb^J]
{ Rs<li\GS
return sFilePath; o0Y {k8
} m4.IaBn/
kCWaji_x%
kCO`JAH#
public void setSFilePath(String value) !vB8Pk"
{ n.{Ud\|
sFilePath = value; mBC?Pg
} SW ^F
G G]4g)O5
k/&~8l.$
public String getSFileName() -c"nx$
{ %B&y^mZv*\
return sFileName; [nO\Q3c|@$
} o+o'!)
A3VXh^y+
kDAPT_Gid
public void setSFileName(String value) c5& _'&
{ tp-PE?
sFileName = value; ~9Nn8g6
} gi|j! m
06FBI?;|=
aB6F<"L,
public int getNSplitter() >8$]g
{ hP1H/=~
return nSplitter; x4&<Vr
} =@F1J7
?=X G#we
XN@F6Gj
public void setNSplitter(int nCount) biy1!r
{ $n30[P@p;
nSplitter = nCount; 3_:J`xX(4
} D\}A{I92F4
} TmZ% ;TN
&R\t<X9 n
a9hK8e
/* Sl,\<a
**Utility.java @j/UDM
*/ :`~;~gW<
package NetFox; k?%?EsR
Bg"KNg
2UPqn#.3
public class Utility { 7q2G/_
=i_ s#v[Y
3dlL?+Y#
public Utility() }IM*Vsk
{ \t6k(5J
]m _<lRye
,P&.qg i=(
} 5 *8V4ca
owz6j:
//线程睡眠 z?NMQ8l|:6
public static void sleep(int nSecond) 9A@/5Z:v5W
{ 8U98`# i
try{ yMdE[/+3
Thread.sleep(nSecond); R4 8w\?L
} >}& :y{z~
catch(Exception e) VI{!ZD]
{ 'jr\F2
e.printStackTrace (); 'G6g yO/K
} I\%a<
} S?ypka"L
'&XL|_Iq
//日志 w}wABO
public static void log(String sMsg) Y8c#"vm(
{ CK<Wba
System.err.println(sMsg); =0Z^q0.
} `QpkD8
pX5#!)
%XX(x'^4
public static void log(int sMsg) ~N<zv({lG
{ T d E.e(
System.err.println(sMsg); gj(|#n5C
} Fx6c*KNX3
} =l7@YCj5c
- '<K_e;
I?2S{]!?
/* cPFs K*w
**TestMethod.java fl8~*\;Xu
*/ M0+xl+c+
package NetFox; 4f)B@A-
P!c.!8C$
]LcCom:]
public class TestMethod { 4=BIYC"Lu
WOw( -
)Z.v fc
public TestMethod() 3sh}(
{ ///xx/weblogic60b2_win.exe 4^3}+cJ7j
try{ d:j65yu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :eL{&&6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `%%/`Qpj;
SiteFileFetch fileFetch = new SiteFileFetch(bean); zSJSus
fileFetch.start(); eflmD$]SW
} })v`` +
catch(Exception e){e.printStackTrace ();} ! MTmG/^
O)bc8DyI
G1RUu-~+
} q9)]R
e}xx4mYo
.paKV"LJ
public static void main(String[] args) V8Lp%*(3
{ $,@PY5r
new TestMethod(); DW@|H
} GkOZ=ej
} `#/0q*$
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