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)); U&3*c+B4
} :/%Vpdd@
for(int i=0;i<nEndPos.length-1;i++) ^MJGY,r6b
{ hCT%1R}rKr
nEndPos = nStartPos[i+1]; #4//2N
} R~w(]
nEndPos[nEndPos.length-1] = nFileLength; 0dkM72p
} @LL&ggV?
} yekIw
F`I-G~e
a LmVOL{
//启动子线程 &ApJ'uC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xe+&/J5b
for(int i=0;i<nStartPos.length;i++) d;<n [)@
{ }7=a,1T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DhZtiqL#_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Xq>e]#gR
nStartPos,nEndPos,i); -;P<Q`{I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GoEIY
fileSplitterFetch.start(); z{#F9'\&
} f6L_uk`{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zW0AB8l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &vMH AZd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :LBe{Jbw
nEndPos = " + nFileLength); q<yH!
// fileSplitterFetch[nPos.length-1].start(); Yn<0D|S;X
uAjGR
<Z m ,q}
//等待子线程结束 gv[7h'}<
//int count = 0; l(]\[}.5
//是否结束while循环 5&X
boolean breakWhile = false; Ve8!
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)%y~{j+M
while(!bStop) .v" lY2:N
{ rd,mbH[<C
write_nPos(); 6ZG)`u".("
Utility.sleep(500); D`t e|K5
breakWhile = true; rmMO-!s
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pz&=5F
for(int i=0;i<nStartPos.length;i++) ;n;^f&;sJ
{ =` i 7?
if(!fileSplitterFetch.bDownOver) gw*d"~A
{ Xl/G|jB9
breakWhile = false; #`p>VXBj!
break; /5x`TT
} T),:8/
} huF L [
if(breakWhile) ,g,jY]o
break; y2+a2
=O;SXzgE
jVA~]a
//count++; jYy0^)6X(
//if(count>4) _"sRL}-Z
// siteStop(); w@: ]]R
} &1h3o^K
dJLJh*=AG
sd[QtK^
System.err.println("文件下载结束！"); R82Y&s;
} y:A0!75
catch(Exception e){e.printStackTrace ();} fjWh}w8
} gNqV>p
aydal9M
}=|ZEhtOp
//获得文件长度 KvD$`"L/CT
public long getFileSize() {cv;S2
{ _#gsR"FZ$
int nFileLength = -1; wi9|
try{ Q jBCkx]g
URL url = new URL(siteInfoBean.getSSiteURL()); Yjl0Pz.q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }-L@AC/\#
httpConnection.setRequestProperty("User-Agent","NetFox"); WvJ?e
MJG%HakK0
5i^vN"J
int responseCode=httpConnection.getResponseCode(); tbPPI)lu
if(responseCode>=400) p&4n3%(R@
{ ZWa#}VS}-n
processErrorCode(responseCode); OV/FQH;V
return -2; //-2 represent access is error )j6>b-H
} >1~`tP
.]e6TFsrO
btF%}<o)
String sHeader; _Y|kX2l S@
cik@QN<[0
O0{
for(int i=1;;i++) U]D.z}0
{ K%}I}8M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q#Y3%WF
//Utility.log(in.readLine()); v 2GhR*
sHeader=httpConnection.getHeaderFieldKey(i); O<h#|g1
if(sHeader!=null) `az`?`i7
{ cA%U
if(sHeader.equals("Content-Length")) Uu X"AFy~\
{ s4$m<"~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4sj%:
break; 4:@|q:DR
} I.u,f:Fl'
} 3rY /6{
else Mak9qaWqF>
break; BZ<z@DJp
} GzXP
} ]'h)7
catch(IOException e){e.printStackTrace ();} GF!{SO4
catch(Exception e){e.printStackTrace ();} GnOo+hB
v,+l xY
h<K;VpL6
Utility.log(nFileLength); N ]7a=
B%@!\D#
]2%P``Yj
return nFileLength; \r%Vgne-g
} VQ?H:1R
9`v:$(I
QiweM?-
//保存下载信息（文件指针位置） |<|,RI?
private void write_nPos() aTh%oBrtP
{ NydW9r:T
try{ k6-n.Rl01
output = new DataOutputStream(new FileOutputStream(tmpFile)); mF}k}0
output.writeInt(nStartPos.length); JX)z<Dz$
for(int i=0;i<nStartPos.length;i++) /V<`L
{ tMZ(s
// output.writeLong(nPos); ?+O|mX}`-
output.writeLong(fileSplitterFetch.nStartPos); d95N$n
output.writeLong(fileSplitterFetch.nEndPos); (1,#=e+
} W79A4l<
output.close(); c'+r[rSn1
} ;]M67ma7C
catch(IOException e){e.printStackTrace ();} 'D"K`Vw
catch(Exception e){e.printStackTrace ();} R[9PFMn
} ]XGn2U\
4D8yb|o
*6D%mrK
//读取保存的下载信息（文件指针位置） !;aC9VhSU
private void read_nPos() ]2Fo.n
{ FFeRE{,
try{ "$IwQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~}0hN]*G
int nCount = input.readInt(); K^vp(2
nStartPos = new long[nCount]; z){UuiUM+=
nEndPos = new long[nCount]; !-RpRRR[Co
for(int i=0;i<nStartPos.length;i++) +R#`j r"
{ SfobzX}~Jh
nStartPos = input.readLong(); :/[YY?pg-
nEndPos = input.readLong(); [9U srpYi
} ;9 &1JX
input.close(); .&Pe7`.BE
} DYKV54\ue
catch(IOException e){e.printStackTrace ();} eAYW%a
catch(Exception e){e.printStackTrace ();} ~`>26BWQz
} :z} _y&]
`;qv}
xFm{oJ!]&
private void processErrorCode(int nErrorCode) +Q!xEfpO;
{ SxW}Z_8x
System.err.println("Error Code : " + nErrorCode); p@8^gc
} ]t*P5
FV6he[,
7k t7^V<
//停止文件下载 q\b ?o!#_
public void siteStop() ,o>pmaoLs
{ eN<pU%7
bStop = true; \m~\,em
for(int i=0;i<nStartPos.length;i++) v6P~XK}G
fileSplitterFetch.splitterStop(); R`C_CsXir
W8yfa[z~J
;Q>3N(
} W3V{Xk|
} LYy:IBI7_
//负责部分文件的抓取 ({_:^$E\
**FileSplitterFetch.java Ul713Bjz
*/ {8Jk=)(md
package NetFox; <#p|z`N
-KwL9J4u
ilRm}lU|x
import java.io.*; %QsSR'`
import java.net.*; mf]( 3ZL
X\^& nLa
svq9@!go
public class FileSplitterFetch extends Thread { M`C~6Mf+
k`7.p,;}U
zUEfa!#?
String sURL; //File URL 4=F]`Lql
long nStartPos; //File Snippet Start Position %AEK[W+0
long nEndPos; //File Snippet End Position KB,~u*~!
int nThreadID; //Thread's ID n#^?X
boolean bDownOver = false; //Downing is over Vi?~0.Z%
boolean bStop = false; //Stop identical gLxT6v5wk.
FileAccessI fileAccessI = null; //File Access interface *L4]\wf
_czbUl
'^F|k`$r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \;B$hT7z*
{ Zn<(,e
this.sURL = sURL; Gxh~
this.nStartPos = nStart; 4j@kMe;RjZ
this.nEndPos = nEnd; ySuLt@X
nThreadID = id; zA'gb'MmW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -0KbdHIKb'
} L=$?q/=-
-M1~iOb
c6Yf"~TD0
public void run() csFJ5
{ WJY4>7}{B@
while(nStartPos < nEndPos && !bStop) N+C)/EN$
{ \o62OfF!
FU(}=5n
zhA',p@K?_
try{ "doU.U&u
URL url = new URL(sURL); o! 2n}C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3!"b guE
httpConnection.setRequestProperty("User-Agent","NetFox"); u_p7Mcb
String sProperty = "bytes="+nStartPos+"-"; |`k1zc)9
httpConnection.setRequestProperty("RANGE",sProperty); RvPniT(<?
Utility.log(sProperty); PV]k3&y
w$b+R8.n)
y=oVUsG
InputStream input = httpConnection.getInputStream(); (N*<\6kr
//logResponseHead(httpConnection); BS-:dyBw
! =\DC,-CB
s#+"5&!s
byte[] b = new byte[1024]; _d\u!giy
int nRead; C"U[ b%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rTP5-4
{ HeT6Dv
nStartPos += fileAccessI.write(b,0,nRead); /jjW/lr
//if(nThreadID == 1) o%/-5-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]{Mci]H6T
} <uBhi4
#Cg}!38
G.-h=DT]
Utility.log("Thread " + nThreadID + " is over!"); q:2aPfo&
bDownOver = true; *;OJ~zT
//nPos = fileAccessI.write (b,0,nRead); [V> :`?
} )p/=u@8_f
catch(Exception e){e.printStackTrace ();} 3WO#^}t
} B@"SOX
} kW<Yda<a
pBg|n=^
b"R, p=M
//打印回应的头信息 5#TrCPi6A
public void logResponseHead(HttpURLConnection con) KdOh'OrT9.
{ D0Vyh"ua
for(int i=1;;i++) H9Y2n 0
{ e(OwS?K
String header=con.getHeaderFieldKey(i); D4=..;
if(header!=null) IdV,%d{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,YP1$gj
Utility.log(header+" : "+con.getHeaderField(header)); "<PoJPh
else [):{5hMA
break; 97qtJ(ESI
} 5"-una>D
} } * ?n?'
h*;g0QBkl
V-D}U$fw
public void splitterStop() Sk6b`W7$
{ ;mf4U85
bStop = true; =_$XP
} dN$ 1$B^k
a"0B?3*r46
4 [R8(U[g
} RLYU\@kK?
18DTv6?QG
M>*0r<qn
/* E;6Y? vJ
**FileAccess.java ~-XOvKJb
*//文件访问(定位，写) YMc8Q\*B
package NetFox; X+]L-o6I2
import java.io.*; rao</jN.9
?1GY%-
55 S\&Ad$
public class FileAccessI implements Serializable{ T-L|Q,-{-
u-AWJc+F.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V,>+G6e
RandomAccessFile oSavedFile; *'UhlFed
long nPos; 0K=Qf69Y
>.DF"]XM
|A ;o0pL
public FileAccessI() throws IOException Zu\p;!e
{ Q0pC4WJ`
this("",0); !1ML%}vvB,
} t{/hkXq]
AddGB^7yl
iBG`43;
public FileAccessI(String sName,long nPos) throws IOException *)MX%`Z}
{ BQyvj\uJ
oSavedFile = new RandomAccessFile(sName,"rw"); 6-mmi7IfO
this.nPos = nPos; VK@$JwdL
oSavedFile.seek(nPos); kP7a:(P_g
} |0tg:\.
Hu<p?mF#
PV?]UUc'n<
public synchronized int write(byte[] b,int nStart,int nLen) E|pk.
{ 1|o$X
int n = -1; J__;.rnk
try{ c]6V"Bo}A
oSavedFile.write(b,nStart,nLen); %oAL
n = nLen; Nc{]zWL9
} cvKV95bn
catch(IOException e) u K'<xM"%T
{ >R(8/#|E
e.printStackTrace (); D,MyI#
} Q(lku"U'
RXBb:f
3@&bxYXm
return n; d4%dIR)
} N6h1|_o
$Z/klSEf
;P3>>DZ
} 0Qm"n6NQ
]$3+[9x'
B]1HS`*7
/* QjLji+L
**SiteInfoBean.java !L77y^oV
*/ &ik$L!iX
package NetFox; DR6]-j!FK
B#]_8svO
Yb}w;F8(
public class SiteInfoBean { mG_BM/$
gA_krK,Z
s|Zx(.EP
private String sSiteURL; //Site's URL 8zZSp
private String sFilePath; //Saved File's Path ^;zWWg/d
private String sFileName; //Saved File's Name en>9E.?N
private int nSplitter; //Count of Splited Downloading File s;J\Kc?"|
]c}=5m/
ymtd>P"
public SiteInfoBean() :7\9xH
{//nSplitter的缺省值为5 h4Ia>^@
//default value of nSplitter is 5 B20_ig:
this("","","",5); +vz`go
} 2/@D7>F&g
>\ZR*CS
k5@d! }#c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8a9RML}G<
{ =<{ RX8
sSiteURL= sURL; {rC~P
sFilePath = sPath; S8%n.<OB
sFileName = sName; u?kD)5Nk
this.nSplitter = nSpiltter; ~s#e,Kav"
:M j_2
kM!V.e[g
} ?>V6P_r>
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public String getSSiteURL() A W)a">|
{ t[EfOQ
return sSiteURL; &!jq!u$(
} c&f y{}10
!%xP}{(7
'"'Btxz
public void setSSiteURL(String value) H] k'?;
{ jJ~Y]dQi
sSiteURL = value; zE`R,:VI
} 0+EN@Y^dAV
Uki9/QiX>
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public String getSFilePath() .^[_V
{ .$Bwb/a
return sFilePath; B,_`btJh
} $b>}C= gt
HM&1yubh#
MdC<4^|
public void setSFilePath(String value) K;U39ofW
{ kX[fy7rVt
sFilePath = value; `tE^jqrke5
} O"*`'D|hK
ni6r{eSQ
2yKz-"E
public String getSFileName() $%PVJs
{ D|_V<'
return sFileName; gWrAUPS[
} %y"J8;U
vG Vd
"+|L_iuNQ
public void setSFileName(String value) s&'BM~WI
{ !gH9ay
sFileName = value; ~O;y?]U
} mJC3@V s
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#U=;T]!'$
public int getNSplitter() \t3qS eWc/
{ * OsU Y=;
return nSplitter; o>c^aRZ{
} #SkX@sl@
8g*hvPc
*7" L]6
public void setNSplitter(int nCount) 4_LQ?U>$
{ #Qbl=o4
nSplitter = nCount; '#Dg8/r!
} {J]-<:XD
} YQgNv`l}
],lV}Mlg*
|d7$*7TvV
/* }+RB=#~o
**Utility.java 6)e5zKW!?
*/ ?znSx}t
package NetFox; `cr(wdvI
[pgZbOIN37
]hE="z=n
public class Utility { 4nkE IZ
v27Ja .tA
7@~tVxB;
public Utility() R1ktj
{ fSA)G$b]
nl1-kB)$e|
61_f3S(u
} Vq ^]s$'
!gP0ndRJ=
//线程睡眠 Yck~xt&]
public static void sleep(int nSecond) q\$6F)ha3
{ cxP6-tV%
try{ c ~Fdx
Thread.sleep(nSecond); naNyGE7)
} TJy4<rb
catch(Exception e) }$gmK
{ M>l^%`
e.printStackTrace (); R,Oe$J<
} {6 .o=EyM{
} \cuS>G
x<B'.3y
//日志 *'ZN:5%H
public static void log(String sMsg) ?m;;D'1j
{ RuAlB*
System.err.println(sMsg); Kt/)pc
} AQ{zx1^2>K
V#83!
3HiFISA*
public static void log(int sMsg) Z=+03
{ `/Y+1 aD
System.err.println(sMsg); q'S =Eav8
} X-JV'KE}^z
} w1|Hy2D`0
MZv\ C
i$UQbd
/* HJhH-\{@
**TestMethod.java S>_27r{
*/ ;-@=
package NetFox; }zMf7<C
B|o%_:]+E
>a>fb|r
public class TestMethod { {0yu
Xm_$ dZ
smU4jh9S
public TestMethod() $v27]"]
{ ///xx/weblogic60b2_win.exe 0 bSA_
try{ cF+ X,]=6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6*XM7'n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); svhrf;3:
SiteFileFetch fileFetch = new SiteFileFetch(bean); (f1M'w/OD
fileFetch.start(); V@ :20m
} +=3CL2{An
catch(Exception e){e.printStackTrace ();} 9$l>\.6
``QHG&$/
0[a}n6XTk
} P-Su5F
2x}6\t
/c-nE3+rn
public static void main(String[] args) ,Og4 ?fS
{ _ PWj(});
new TestMethod(); ]/dVRkZeAE
} TKI$hc3|L
} D`o<,Y
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