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)); &8Zeq3~
} T0g0jr{
for(int i=0;i<nEndPos.length-1;i++) j0AwL7
{ }|AX_=a
nEndPos = nStartPos[i+1]; L?C\Q^0"`G
} |Es0[cU
nEndPos[nEndPos.length-1] = nFileLength; U> W|(Y
} (viWY
} =ntftSH
KCE=|*6::|
5n:nZ_D
//启动子线程 g&Z"_7L~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N A8 sN
for(int i=0;i<nStartPos.length;i++) S3ErH,XB.
{ `a-Bji?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |4=ihB9+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gRHtgR)T3
nStartPos,nEndPos,i); ?'Cb-C_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); { AFf:[G
fileSplitterFetch.start(); 'CgV0&@
} V>6QPA^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B<Ol+)@,}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qbH%Hx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U4]30B{;H
nEndPos = " + nFileLength); i)=m7i
// fileSplitterFetch[nPos.length-1].start(); X|,["Az 8
Pv~:gP
YDW|-HIF
//等待子线程结束 x9h?e`
//int count = 0; tbg*_ZQO u
//是否结束while循环 )u<eO FI+
boolean breakWhile = false; ]}.0el{
WXLK89ev\
E!uJ6\
while(!bStop) [8.-(-/;
{ I4ebkPgf
write_nPos(); 7aV$YuL)X~
Utility.sleep(500); $_wo6/J5+D
breakWhile = true; ,}KwP*:Z
-U7,k\g
l(#1mY5!q8
for(int i=0;i<nStartPos.length;i++) grc:Y
{ >}CEN
if(!fileSplitterFetch.bDownOver) M%3Wy"YQ,n
{ GKCM|Y
breakWhile = false; _p0)vT
break; f$vwuW
} ?HV}mS[t
} ndqckT@93
if(breakWhile) eIsT!V"7
break; Z0aUHWms
wE?CvL
7N| AA^I
//count++; B@"J]S
//if(count>4) -A}zJBcR
// siteStop(); "w9`cz9a~J
} YKY2Cw
yWNOG 2qAP
&f"T,4Oh
System.err.println("文件下载结束！"); 7|Xe&o<n
} g>_OuQ|c
catch(Exception e){e.printStackTrace ();} b;*c:{W)
} _H8*ReFG
Zb"jB$58
PYu$1o9+N
//获得文件长度 a_MFQf&KV
public long getFileSize() 1\y@E
{ w763zi{
int nFileLength = -1; Od-Ax+Hp
try{ WtVf wC_
URL url = new URL(siteInfoBean.getSSiteURL()); /9Z!p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M1EOnq4-
httpConnection.setRequestProperty("User-Agent","NetFox"); Jr]gEBX
*!w25t
2$tQ @r
int responseCode=httpConnection.getResponseCode(); yyjw?#\8
if(responseCode>=400) F{\=PCZ>7
{ @y5=J`@=
processErrorCode(responseCode); =DC3a3&%
return -2; //-2 represent access is error ~;8I5Sge
} NJm-%K
ioWo ]
\sITwPA[z
String sHeader; ' Rc#^U*n
Z%OW5]q
e}e6r3faz
for(int i=1;;i++) {yS;NU`2
{ WFem#hq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7E\g &R.
//Utility.log(in.readLine()); 8ljuc5,J
sHeader=httpConnection.getHeaderFieldKey(i); uFo/s&6K
if(sHeader!=null) lm*g Gy1i
{ 2T?TM! \Q
if(sHeader.equals("Content-Length")) 0<Q*7aY
{ z&F5mp@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )b0];&hw]
break; 7h`^N5H.q
} H99xZxHZ{
} Bzw19S6y
else ?A&%Cwj
break; G|*G9nQ
} 7&foEJ3q
} xNIGO/uI~
catch(IOException e){e.printStackTrace ();} #A )Ab%r8"
catch(Exception e){e.printStackTrace ();} K{2h9 ]VF
#)]E8=}
WqQU@sA
Utility.log(nFileLength); #w|5jN?
ke]Yfwk
G?ig1PB"#
return nFileLength; wDKELQ(yH
} >vAN(3Idu
0X>T+A[E
~b6GrY"vB
//保存下载信息（文件指针位置） ? |VysJ
private void write_nPos() TF2KZL#A|
{ pV=@sz,G
try{ 0>FE%
output = new DataOutputStream(new FileOutputStream(tmpFile)); RX>2~^
output.writeInt(nStartPos.length); &a6,ln:P
for(int i=0;i<nStartPos.length;i++) ?Oc -aa
{ RG1\=J$:E
// output.writeLong(nPos); X!c?CL
output.writeLong(fileSplitterFetch.nStartPos); w.^yP7:
output.writeLong(fileSplitterFetch.nEndPos); +?AW>&68y
} $8g42LR'
output.close(); p9iu:MucD<
} V;;#/$oU:4
catch(IOException e){e.printStackTrace ();} U=QA e
catch(Exception e){e.printStackTrace ();} w & P&7
} ]\dHU.i
NzlAC
Ao"C<.gUYP
//读取保存的下载信息（文件指针位置） 2y%R:Mu
private void read_nPos() ]r959+\$
{ Dr+Ps
try{ 12OlrU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ShGp^xVj
int nCount = input.readInt(); oY.\)eJ~>
nStartPos = new long[nCount]; ]0-<>
nEndPos = new long[nCount]; vQHpf>o
for(int i=0;i<nStartPos.length;i++) {SdO9Yy?@7
{ FmD +8=
nStartPos = input.readLong(); VB"(9O]
nEndPos = input.readLong(); iRve)
} ix*muVBj.
input.close(); x0<^<D&Q
} 0T9.M(
catch(IOException e){e.printStackTrace ();} " "%#cDR
catch(Exception e){e.printStackTrace ();} LGVlc@0'
} 1-o V-K
`D2Mss$!
ArXl=s';s4
private void processErrorCode(int nErrorCode) ti2
{ n&d/?aJ7a\
System.err.println("Error Code : " + nErrorCode); Nog(VN4I&
} X<euD9?
mb{q(WEPP
YgimJsm
//停止文件下载 N RSU+D-z
public void siteStop() P }Te"Y
{ Uk'U?9O
bStop = true; vpLMhf`
for(int i=0;i<nStartPos.length;i++) R=$Ls6z
fileSplitterFetch.splitterStop(); Qxq-Mpx{
[r9d<Zi}{
nzuF]vo
} xS+rHC
} eY}V9*.v
//负责部分文件的抓取 wS$46M<
**FileSplitterFetch.java u"FjwF?
*/ UA(;fZ@
package NetFox; ]w[ThHRJ
A*i_|]Q
sE9Ckc5
import java.io.*; *eGM7o*\X
import java.net.*; 8x{Hg9
h(N=V|0
%5Rq1$D
public class FileSplitterFetch extends Thread { M-Sv1ZLh
:Q-F9o J
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String sURL; //File URL 9o_-=>(
long nStartPos; //File Snippet Start Position yL&/m~{s
long nEndPos; //File Snippet End Position ] .5OX84
int nThreadID; //Thread's ID '[fZt#
boolean bDownOver = false; //Downing is over ~L'nzquF
boolean bStop = false; //Stop identical f#OQ (WTJE
FileAccessI fileAccessI = null; //File Access interface ZqK]jT6V/X
%rcFT_
T4GW1NP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N`1r;%5
{ ( 3;`bvYH"
this.sURL = sURL; P']Y( !L
this.nStartPos = nStart; *rf$>8~$n
this.nEndPos = nEnd; 6N3@!xtpi
nThreadID = id; *Hunp Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \ja `c)x
} &HL{LnLP@/
_]o5R7[MQ
/s`;9)G]9
public void run() .$wLLE^*
{ @a(oB.i
while(nStartPos < nEndPos && !bStop) 784;]wdy\
{ ?D=8{!R3
gp/YjUH7k8
|M E{gy`5
try{ w1i?#!|
URL url = new URL(sURL); )eR$:uO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dtTlIhh1V
httpConnection.setRequestProperty("User-Agent","NetFox"); ~6d5zI4\
String sProperty = "bytes="+nStartPos+"-"; 3cThu43c
httpConnection.setRequestProperty("RANGE",sProperty); .Dx2 ;lj
Utility.log(sProperty); }cW#045es
T2|:nC)@
ML=z<u+
InputStream input = httpConnection.getInputStream(); ^:z7E1~
//logResponseHead(httpConnection); YiZx{5
) b:4uK A
sykFSPy`'
byte[] b = new byte[1024]; sN]Z #7
int nRead; rPO}6lsc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >EIrw$V$
{ x'i0KF
nStartPos += fileAccessI.write(b,0,nRead); bl.EIyG>
//if(nThreadID == 1) wPH+n-&e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U~/ID
} VDiOO
DL4iXULNY
?Aw3lH#:
Utility.log("Thread " + nThreadID + " is over!"); Qlh?iA
bDownOver = true; !Uy>eji}
//nPos = fileAccessI.write (b,0,nRead); )!,@m>0v{
} j38 6gL
catch(Exception e){e.printStackTrace ();} +c?ie4
} 7K:FeW'N
} -tyaE
yVYkuO
>76 |:Nq
//打印回应的头信息 <Uwwux<v
public void logResponseHead(HttpURLConnection con) U>A6eWhH
{ TQ-KkH}y
for(int i=1;;i++) jL_5]pzJ
{ a8QfkOe
String header=con.getHeaderFieldKey(i); G_(ct5:_"!
if(header!=null) )7AM3%z1?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Efr3x{ j
Utility.log(header+" : "+con.getHeaderField(header)); 4Py3I9
else D|TR!
break; b1)\Zi
} v,0<9!'v
} 7d9Z/J@>
(hsZ
]]y[t|6
public void splitterStop() **HrWM%?8o
{ L*^ V5^-
bStop = true; .vaJAvg
} 5!h<b3u>]
bd{\{[^S!
K?YEoz'y[
} {aIZFe}B
dEET}s\
y@ .b 4
/* FfSI n3
**FileAccess.java r=\P!`{5
*//文件访问(定位，写) Z@oKz:U
package NetFox; BA*&N>a
import java.io.*; z Lw(@&
8!4[#y<
DaDUK?
public class FileAccessI implements Serializable{ O! (85rp/
JZw^W{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DaCblX
RandomAccessFile oSavedFile; nX 8B;*p6b
long nPos; g]4yAV<2
M:(&n@e
)f[C[Rd
public FileAccessI() throws IOException +C5#$5];
{ XHNkQe
this("",0); ==`Pb
} %ET # z!
?RJdn]`4j
07Y_^d
public FileAccessI(String sName,long nPos) throws IOException X TM$a9)
{ y9ip[Xn-$:
oSavedFile = new RandomAccessFile(sName,"rw"); kwc*is
this.nPos = nPos; 23k)X"5
oSavedFile.seek(nPos); ]_\AHnJ
} pU@YiwP"]x
L6xB`E9
AoU_;B\b%
public synchronized int write(byte[] b,int nStart,int nLen) q#m!/wod
{ J@gm@ jLc
int n = -1; "u5KbJW
try{ PY\W
oSavedFile.write(b,nStart,nLen); T+(M8qb
n = nLen; +K&?)?/=
} *?p ^6vO
catch(IOException e) [9J:bD
{ r;'i<t{P
e.printStackTrace (); 6"%@L{UQ
} Z,SY N?@
(H2ylMpQt
bl`D+/V
return n; i)[kubM
} YQx?* gZS
1]Lhk?4t
%rw}u"3T
} HM 90Sb
~;!BDLMC6
V07VwVD
/* @"0uM?_)-
**SiteInfoBean.java #)FDl70S8
*/ 73VQ@Jn
package NetFox; Ej{+U
!. p
hAlPl<BO#V
public class SiteInfoBean { m|lM.]2_
]~'9
aU4R+.M7@
private String sSiteURL; //Site's URL brj[c>ID
private String sFilePath; //Saved File's Path aj?2jU~Pq
private String sFileName; //Saved File's Name 8<Xq=*J+
private int nSplitter; //Count of Splited Downloading File }a'cm!"
.Jptj
gU+ss
public SiteInfoBean() WqR7uiCi
{//nSplitter的缺省值为5 el}hcAY/RP
//default value of nSplitter is 5 X:U=MWc>
this("","","",5); tg3zXJ4k_
} [z^Od
!ZX&r{pJp
o>.AdZby
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2G ZF/9}
{ K[e`t%2_
sSiteURL= sURL; xUIvLH=
sFilePath = sPath; `t%|.=R
sFileName = sName; e~3]/BL
this.nSplitter = nSpiltter; @`5QG2
KM5jl9Vv
<>VIDE
} Qg[heND
?vMK'"
/q T E
public String getSSiteURL() b-2pzcK{#
{ q)vK`\Y
return sSiteURL; )sRN!~
} (v]P<3%
U&`6&$]
v: giZxR
public void setSSiteURL(String value) !;TR2Zcn
{ ccRlql(
sSiteURL = value; 9U&~(;
} !X%S)VSMU
K4_~ruhr
N`f!D>b:dn
public String getSFilePath() Rq"VB.ef&{
{ dJloH)uJZ>
return sFilePath; 04P.p6
} c^rC8E
*U:VM'a
GahaZ F
public void setSFilePath(String value) oN_S}o
{ #,t2*tM
sFilePath = value; @<|6{N<
} sf fV.cC`
"v@);\-V
6euR'd^Qi
public String getSFileName() R_t~UTfI;
{ "tfn?n0
return sFileName; 4tbw*H5!5
} Um/CR!
o1 jk=
bh{E&1sLh
public void setSFileName(String value) [SK2x4
{ G}182"#4
sFileName = value; C\y[&egww
} 2=jd;2~
kZJt~}
eH ;Wfs2f
public int getNSplitter() f#*h^91x
{ f;e_04K
return nSplitter; :x8Jy4L
} Ga]47pQ"F
d#E(~t(^
-K:yU4V
public void setNSplitter(int nCount) Qk?jGXB>^
{ AqKHjCI
nSplitter = nCount; Cw6>^
} n>u.3wL
} wYZye^7
V+Y|4Y&
R 4DM_u
/* XPar_8I
**Utility.java d^ 2u}^kG
*/ s>LA3kT
package NetFox; uCY(:;[<
F~tm`n8Z
@~JB\j9
public class Utility { P]|J?$1K
y2oB]^z&n
1[26w_B3
public Utility() >`<Ued
{ Mr$# e
aeEw#
OG0r4^6Ly
} &mX5&e
Is4%}J!8
//线程睡眠 :Tlf4y:/w
public static void sleep(int nSecond) *>EI2HX
{ 8dV.nO
try{ l\q*%'Pe
Thread.sleep(nSecond); s@[C&v
} f 1sy9nQs
catch(Exception e) sjkWz2]S
{ w%>aR_G
e.printStackTrace (); 5x:Ift *
} p>2||
} j)g_*\tQ
i58ZV`Rk`
//日志 5W*7qD[m
public static void log(String sMsg) O<}ep)mr
{ }wvwZ`5t
System.err.println(sMsg); hubfK~
} K<$wz/\
It#hp,@e
!F=|*j
public static void log(int sMsg) `'z(--J}`
{ \hjk$Gq
System.err.println(sMsg); s-QM6*
} nAQyxP%
} 3!i.Fmo
Gg 7WmL
jA20c(O
/* y0/WA4,
**TestMethod.java "6NFe!/Y$*
*/ Dj-\))L
package NetFox; o0zc}mm
08<k'Oi]
F{#N6,T
public class TestMethod { !yoSMI-
)e4WAlg8c
O"_erH\nk
public TestMethod() 2rK-X_}
{ ///xx/weblogic60b2_win.exe h Jfa_
try{ .8u$z`j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `_NnQ%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $=e&q
SiteFileFetch fileFetch = new SiteFileFetch(bean); u=p ;A1oy
fileFetch.start(); ]_^"|RJ
} \_m\U.*
catch(Exception e){e.printStackTrace ();} .V5q$5j
ib5;f0Qa
oV0LJ%
} ga4/,
e%P+KX
6F|Hg2tpz
public static void main(String[] args) DFt=%aV[
{ _hAj2%SL
new TestMethod(); 0EL\Hd
} Y9IJ
} K7t&fDI
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