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)); fPrb%
} Ivjw<XP6K
for(int i=0;i<nEndPos.length-1;i++) H%cp^G
{ yXXvs'$R \
nEndPos = nStartPos[i+1]; 2R] XH 0
} YnD#p[Wo^
nEndPos[nEndPos.length-1] = nFileLength; *) } :l
} bHJoEYY^
} QnP{$rT
I)rGOda{
yP%o0n/"x
//启动子线程 55,=[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4$F:NW,v:)
for(int i=0;i<nStartPos.length;i++) shy
{ ,wlbIl~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1wbTqc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ($:y\,5(9I
nStartPos,nEndPos,i); 0IpST
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Db,= 2e
fileSplitterFetch.start(); Wk,6) jS=}
} i[8NO$tN1)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b^%?S8]h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %awVVt{aG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", []rT? -
nEndPos = " + nFileLength); ?n&$m
// fileSplitterFetch[nPos.length-1].start(); Liij{ahm
1N>6rN
'}T;b}&s
//等待子线程结束 s{cKBau
//int count = 0; ;*.(.
//是否结束while循环 w'|&5cS
boolean breakWhile = false; +!Q!m 3/I
E;xMPK$
l3BD <PB2S
while(!bStop) 2DUr7rM
{ [h^f%
write_nPos(); C#ZhsWS!b
Utility.sleep(500); 6{ C Fe|XN
breakWhile = true; [pr 9 $Jr
&7fY_~)B
rQn{L{
for(int i=0;i<nStartPos.length;i++) "NJ,0A
{ y%2%^wF
if(!fileSplitterFetch.bDownOver) a6k(9ZF
{ ^t`f1rGR
breakWhile = false; )&XnM69~b
break; j=FMYd8$y
} Mq76]I%
} \m%J`{Mt
if(breakWhile) g%X&f_@
break; ~c!Rx'
G&.d)NfE
jT{f<P0
//count++; Lr wINVa
//if(count>4) L>0!B8X2
// siteStop(); kpl~/i`4
} =?wMESU
NoJUx['6
I Jqv w
System.err.println("文件下载结束！"); 6aRGG+H
} P$6W`^DZ
catch(Exception e){e.printStackTrace ();} ]c5DOv&
} B'<!k7Ewy
\y[Bu^tk
~."!l'a
//获得文件长度 lfXH7jL2~
public long getFileSize() ]NbX`'
{ ^=Q8]W_*
int nFileLength = -1; r>E\Cco
try{ hx*HY%\P
URL url = new URL(siteInfoBean.getSSiteURL()); `i=JjgG@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^GE^Q\&D&
httpConnection.setRequestProperty("User-Agent","NetFox"); =d}gv6v2S
*Yj~]E0`1
\5t`p67Ve_
int responseCode=httpConnection.getResponseCode(); ESn6D@"
if(responseCode>=400) D&4u63^
{ D~5yj&&T;
processErrorCode(responseCode); sKe,
return -2; //-2 represent access is error ? 7/W>
} 3fm;r5
x(rd$oZO
aB=vu=hF
String sHeader; iJ,M-GHK
YR?3 61FK
<9ePi9D(
for(int i=1;;i++) hU 9\y
{ N 9c8c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q^*G`&w,
//Utility.log(in.readLine()); *^X#Eb
sHeader=httpConnection.getHeaderFieldKey(i); d&NCFx
if(sHeader!=null) P4hZB_.=
{ fL(':W&n-
if(sHeader.equals("Content-Length")) Tld1P69(
{ P{"WlJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0[V&8\S~'T
break; &7$,<9.
} D/gd
} g&{gD^9)4
else )?F$-~7
break; NQDLI 1o
} kX@bv"i
} K~`n}_:
catch(IOException e){e.printStackTrace ();} UedvA9$&;
catch(Exception e){e.printStackTrace ();} /!^L69um
o9_(DJ<{
4kWg>F3
Utility.log(nFileLength); ]|Ow_z8 O
BO?mQu~
- P\S>G.
return nFileLength; KYnW7|*
} Sg/:n,68
!S~,>,yd
=$^Wkau
//保存下载信息（文件指针位置） _7rqXkp%
private void write_nPos() ;[;)P tFz\
{ J ZVr&KZN
try{ C$$"{FfgU"
output = new DataOutputStream(new FileOutputStream(tmpFile)); fn1 ?Qp|
output.writeInt(nStartPos.length); .tZjdNE(h
for(int i=0;i<nStartPos.length;i++) cYZwWMzp
{ wrz+2EP`
// output.writeLong(nPos); !T<z'zZU
output.writeLong(fileSplitterFetch.nStartPos); ` (7N^@
output.writeLong(fileSplitterFetch.nEndPos); "}S9`-Wd|
} [54@irH
output.close(); IW5*9)N?
} [>b '}4
catch(IOException e){e.printStackTrace ();} 2q`)GCES~
catch(Exception e){e.printStackTrace ();} +CsI,Uf4*
} >v^2^$^u
c+@d'yR
o,*folL
//读取保存的下载信息（文件指针位置） 4y|xUO:
private void read_nPos() 4(` 2#
{ 9X 5*{f Y
try{ a/`c ef
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j~+[uzW98
int nCount = input.readInt(); iifc;62
nStartPos = new long[nCount]; a"`g"ZRx
nEndPos = new long[nCount]; ) 1lJ<g#
for(int i=0;i<nStartPos.length;i++) Iq4Kgc
{ 4?9soc
nStartPos = input.readLong(); (Wm/$P;
nEndPos = input.readLong(); &,W_#l{
} D}zOuB,S
input.close(); gGtep*k
} SRA|7g}7W
catch(IOException e){e.printStackTrace ();} 1Pud,!\%q
catch(Exception e){e.printStackTrace ();} qWRNHUd
} %00k1*$
Jo6~r-
Ybs=W<-
private void processErrorCode(int nErrorCode) 844tXMtPB\
{ cJU!zG
System.err.println("Error Code : " + nErrorCode); p{A}p9sjx
} }4bB7,j
v\vE^|-\/
qT4I Y$h
//停止文件下载 zznPD%#Sc
public void siteStop() K$MJ#Zx^
{ Bxn8><
bStop = true; pr0@sri@
for(int i=0;i<nStartPos.length;i++) c[wQJc
fileSplitterFetch.splitterStop(); OoAr%
AIvL#12
F<PWBs%
} naec"Kut
} <.PPs:{8#
//负责部分文件的抓取 >>oASo
**FileSplitterFetch.java <Dt/Rad
*/ 1R5\GKF6o
package NetFox; R$!;J?SS
HI"!n$p
2x<Qt2"
import java.io.*; ,Az`6PW
import java.net.*; Rxvd+8FF
Ft%TnEp
$I}Hk^X
public class FileSplitterFetch extends Thread { xJ[k#?T'
88tFB
()@.;R.Z
String sURL; //File URL 0[Xt,~
long nStartPos; //File Snippet Start Position CX&yjT6`
long nEndPos; //File Snippet End Position eZN3H"H
int nThreadID; //Thread's ID < "L){$
boolean bDownOver = false; //Downing is over ?)Czl4J
boolean bStop = false; //Stop identical &xGfkCP.]
FileAccessI fileAccessI = null; //File Access interface L}e"nzTE6I
<B]i80.
877EKvsiC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q G :jnl
{ j=xtnIq
this.sURL = sURL; \U)2 Tg
this.nStartPos = nStart; @yU!sE:
this.nEndPos = nEnd; Se^/VVm
nThreadID = id; GvZac
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RvyBg:Aj5
} y~]IVl"
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#.\,y>`
public void run() [p( #WM:
{ c-s`>m
while(nStartPos < nEndPos && !bStop) 4! Oa4
{ `5k6s,
o@<6TlZM
|"Xi%CQ2
try{ w+).pcG(*
URL url = new URL(sURL); dbMu6Bm\G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BDRYip[Sa
httpConnection.setRequestProperty("User-Agent","NetFox"); lJ2|jFY9
String sProperty = "bytes="+nStartPos+"-"; #FQm/Q<0
httpConnection.setRequestProperty("RANGE",sProperty); Kh:#S|
Utility.log(sProperty); hSx+{4PZ
$+lz<~R
6yu*a_
InputStream input = httpConnection.getInputStream(); lry&)G=5
//logResponseHead(httpConnection); }l]3m=)
pU:C=hq4
x;ICV%g/
byte[] b = new byte[1024]; :{wsd$Qlj
int nRead; 0XQ".:+h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I9*BENkR
{ zgq_0w~X
nStartPos += fileAccessI.write(b,0,nRead); MUCJ/GF*
//if(nThreadID == 1) v' 9(et
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c5=v`hv
} !ulLGmUn
5|6z1{g8
Zeme`/aBb
Utility.log("Thread " + nThreadID + " is over!"); PBAz`y2
bDownOver = true; YL9t3]
//nPos = fileAccessI.write (b,0,nRead); k[r./xEv+t
} !dbA (
catch(Exception e){e.printStackTrace ();} +/@ZnE9s
} RK~FT/
} shDt&_n
R@7GCj
JR a*;_
//打印回应的头信息 (}~eD
public void logResponseHead(HttpURLConnection con) wCq)w=,
{ w371.84
for(int i=1;;i++) *xv/b=
{ 4ye`;hXy
String header=con.getHeaderFieldKey(i); ?(,5eg
if(header!=null) e&H<lT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (1elF)
Utility.log(header+" : "+con.getHeaderField(header)); XftJ= *
else i"sYf9,
break; N}l]Ilm$34
} 3Q*RR"3
} uZ0 $s$
S\v&{
St3(1mApl
public void splitterStop() WkDn
{ j6R{
bStop = true; 6t7;}t]t
} >+; b>
4M0v1`k
ZB^4(F')H
} :E>n)_^
>Rki[SNb-b
,$6MM6W;-F
/* JIY ^N9_
**FileAccess.java hyvV%z Z
*//文件访问(定位，写) ,I2reG
package NetFox; jC/JiI
import java.io.*; (;2J(GZ:$U
{ck
UB&S 2g
public class FileAccessI implements Serializable{ rt@-Pw!B
-4^@)~Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WW\)B-}T
RandomAccessFile oSavedFile; dnX`F5zd
long nPos; e}Af"LI
vZ nO
H8t{ >C)]
public FileAccessI() throws IOException <E}]t,'3
{ '9p5UC
this("",0); mk`cyN>m
} 9Pob|UA
!iitx U
bF Y)o Z
public FileAccessI(String sName,long nPos) throws IOException kkE)zF
{ $NGtxZp
oSavedFile = new RandomAccessFile(sName,"rw"); bhm~Ii
this.nPos = nPos; $jeDVH
oSavedFile.seek(nPos); (fGJP*YO
} SVs~,
xwH|ryfs,Z
6dS1\Y
public synchronized int write(byte[] b,int nStart,int nLen) #`#aSqGmc
{ dW^_tzfF7
int n = -1; oIL+@}u7
try{ E=1/
oSavedFile.write(b,nStart,nLen); l#vw L15
n = nLen; QRmQ>
} dT@SO
catch(IOException e) SE}RP3dF!
{ sO4}kxZ
e.printStackTrace (); ! ?U^+)^$
} |b'<XQ&l5
k89gJ5B$
(+Kof
return n; '3_B1iAv
} NK#"qK""k
%]sEt{
]BQWA
} hPXVPLm7I
a9EI7pnq
*~<]|H5~
/* E5[]eg~w%{
**SiteInfoBean.java E=_B@VJknW
*/ wyzBkRg.
package NetFox; iJKm27 ">
io?{ew
s8_NN
public class SiteInfoBean { gl7vM
\,bFm,kC?
Y %D*O
private String sSiteURL; //Site's URL WWs[]zr
private String sFilePath; //Saved File's Path g@6X|W5,J
private String sFileName; //Saved File's Name wR<QeH'V
private int nSplitter; //Count of Splited Downloading File :-WCW);N
Jgv>$u
`~+a=Q
public SiteInfoBean() O7'^*"S
{//nSplitter的缺省值为5 BM$tywC
//default value of nSplitter is 5 ,a_{ Y+
this("","","",5); H.mQbD`X
} xE-`Bb
6k=Wt7C
;YXrG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {6y.%ysU
{ Q.E^9giC
sSiteURL= sURL; p$o&dQ=n[
sFilePath = sPath; [qD<U%Hi
sFileName = sName; "T1#*"{j
this.nSplitter = nSpiltter; H- qP>:
pB7Z;&9
8YLZ)k'
} t5v)6|
rKs WS~U
?NzeP?g
public String getSSiteURL() .L{+O6*c
{ nIKT w
return sSiteURL; dVtLYx
} qjEWk."
`::'UfHc
d!z).G
public void setSSiteURL(String value) H6\ x.J^,
{ ihY^~
sSiteURL = value; {*Wwu f.
} )I-?zyL
oS|~\,p"
}~~^ZtJ\
public String getSFilePath() )7%]<2V%
{ u{nWjqrM*5
return sFilePath; n6UU6t{
} uZ?CVluP
j72]_G
+P)[|y +e
public void setSFilePath(String value) !#gE'(J;c
{ -%gd')@SfD
sFilePath = value; nC{rs+P
} /z?7ic0
M"l rwun^
oUKbzr/C
public String getSFileName() 'CAukk|
{ i|{nj\6w^
return sFileName; 0uJzff!|
} DCzPm/#b
lJY=*KB(6
<RVtLTd/
public void setSFileName(String value) {1U*:@j
{ *k]S{]Y
sFileName = value; a`X&;jH0ef
} =X5&au o
&vvx"
H^1 a3L]
public int getNSplitter() f4y;K>u7p
{ ygY+2
return nSplitter; Qbpl$L
} YYr&r.6
E0A|+P '?
SFgIY]
public void setNSplitter(int nCount) bYB}A:
{ (U(x[Df)
nSplitter = nCount; r<"/P`r
} ~teW1lMu(
} EAE\Xv
v]SE?xF{U
6$<o^Ha*R
/* ,fJ(.KI0
**Utility.java WB[G!'
*/ YaT+BRh?
package NetFox; 'wnY>hN
mKn357:
F1*rUsRKN
public class Utility { #TwE??ms
]3u'Qv}o
,(W98}nB
public Utility() z\d2T%^:g(
{ UKQ&TV}0
2.2a2.I1
3C[4!>|
} n(xlad
:bDn.`KG#
//线程睡眠 {^MAdC_
public static void sleep(int nSecond) i*w-Q=
{ 5T3>fw2G
try{ t%B!\]
Thread.sleep(nSecond); RAQ;O
} Vzm+Ew _
catch(Exception e) h`rjDd
{ W&f Py%g
e.printStackTrace (); |5B9tjJ"
} at]Q4
} H[k3)r2
na:^7:I
//日志 gH)B` @
public static void log(String sMsg) $uB(@Ft.
{ CyDf[C)=
System.err.println(sMsg); 7[0k5-
} [E1|jcmQ
o"M^sKz47
U (7P X`1
public static void log(int sMsg) 2Lgvy/uN
{ n<&R"89
System.err.println(sMsg); &+^ Y>Ke
} <qY>d,+E'
} ^uElQI
lG#&1
lA 0_I"b2Y
/* L([>yQZ
**TestMethod.java gt(nZ
*/ A8(PI)Ic.
package NetFox; qk1D#1vl
6mpUk.M"
#h|< >
public class TestMethod { \9zC?Cw
yP]W\W'
R3`W#`
public TestMethod() {;M/J
{ ///xx/weblogic60b2_win.exe iPpJ`i#@+
try{ _cN)q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (kOv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yS3s5C{C
SiteFileFetch fileFetch = new SiteFileFetch(bean); v 8a
fileFetch.start(); eW,Pn'
} M=_CqK*
catch(Exception e){e.printStackTrace ();} IOqyqt'
XPTB,1g+f
Dy@NgHe
} =JH,RQ *
wGX"R5
}"H900WE|
public static void main(String[] args) )pa|uH+N
{ 1*b%C"C
new TestMethod(); gRI|rDC)B
} nDw9
} VSFl9/5?
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