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)); iG;6e~p
} [#_ceg1G
for(int i=0;i<nEndPos.length-1;i++) 2eNm2;
{ (w.B_9#
nEndPos = nStartPos[i+1]; Pw")|85
} g%Z;rDfi
nEndPos[nEndPos.length-1] = nFileLength; <ANKoPNie
} #&2mu
} z|9 ^T@)
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ukw'$Yt2
//启动子线程 dL"v*3Fy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h3:k$`_
for(int i=0;i<nStartPos.length;i++) D526X0
{ "x{S3v4Rb5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /4|qfF3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Uz0mSfBp
nStartPos,nEndPos,i); G -;Yua2\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]?kf;A@
fileSplitterFetch.start(); a}wB7B;,g
} 6ugBbP +^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K46\Rm_:B;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g$<@!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R}0cO^V
nEndPos = " + nFileLength); pY2nv/
// fileSplitterFetch[nPos.length-1].start(); 6} 9A0
)b =$!
W?$ ImW
//等待子线程结束 f.,-KIiF
//int count = 0; 9+L! A
//是否结束while循环 ?.T=(-
boolean breakWhile = false; ?D.]c;PR
3}H94H)]a
(Yx rZ_F'b
while(!bStop) vs.q<i-u
{ OvFZ&S[
write_nPos(); pd|c7D!6U,
Utility.sleep(500); X 6>Pq
breakWhile = true; '\9A78NV{;
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)wKuumet
for(int i=0;i<nStartPos.length;i++) TPkm~>zD.
{ xT@\FwPr
if(!fileSplitterFetch.bDownOver) nI6`/
{ ^,?]]=mE
breakWhile = false; XpM#0hm
break; `+<5QtD
} pdE=9l'
} 7_JK2
if(breakWhile) )q#b^( v
break; "xh]>_;&'
W nVX)o
2LgRgY{Bl
//count++; ~oOOCB
//if(count>4) yXDf;`J
// siteStop(); c=ZX7U
} E;h#3 B9
s|qB;
N&=,)d~M
System.err.println("文件下载结束！"); -8-Aqh8|
} ^7(zoUn:
catch(Exception e){e.printStackTrace ();} 0.?|%;^ib
} FO*Py)/rX
D[U5SS!)
/P,J);Y
//获得文件长度 ed&,
public long getFileSize() IH{g-#U
{ dLv\H&
int nFileLength = -1; = uOFaZ4
try{ 0`_Gj{:L
URL url = new URL(siteInfoBean.getSSiteURL()); 4).q+{#k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #MI}KmH
httpConnection.setRequestProperty("User-Agent","NetFox"); o\2#o5#
];IUiS1
s7=]!7QGS!
int responseCode=httpConnection.getResponseCode(); -FJ5N}R
if(responseCode>=400) yaeX-'(Fv[
{ k{9s>l~'
processErrorCode(responseCode); 5HmX-+XpK
return -2; //-2 represent access is error y*P[*/g
} c/pT2/y
KaOS!e'
HmQuRW
String sHeader; w2Pkw'a{
-[ F<u
Vk[m$
for(int i=1;;i++) 3EAu#c@q"
{ Q~uj:A]n<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G:f]z;Xdp
//Utility.log(in.readLine()); o-/Xa[yC
sHeader=httpConnection.getHeaderFieldKey(i); ]{dg"J
if(sHeader!=null) "Sl";.
{ h4ZrD:D0\
if(sHeader.equals("Content-Length")) BjJ+~R
{ m\j'7mZ1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6N6d[t"
break; t+ Fm?
} (0^u
} J5IQ
else 2E;*kKw[
break; eja_+`cJ
} z$;z&X$j
} DN!:Rm uc
catch(IOException e){e.printStackTrace ();} oc>,5 x
catch(Exception e){e.printStackTrace ();} M,:GMO:?a
\Z<' u;
J,k9?nkY /
Utility.log(nFileLength); 5^[V%4y>
WG<D+P
AOhsat;O`
return nFileLength; p.&FK'&[0
} _v<EFal
+K]kGF
-cEjB%Neo
//保存下载信息（文件指针位置） )mJl-u[0+
private void write_nPos() 4mUQVzV
{ <T<?7SE+
try{ eZT923tD
output = new DataOutputStream(new FileOutputStream(tmpFile)); +ImPNwrY
output.writeInt(nStartPos.length); u9QvcD^'z
for(int i=0;i<nStartPos.length;i++) .\qZkk}2l
{ <[kdF")
// output.writeLong(nPos); =((#kDrN
output.writeLong(fileSplitterFetch.nStartPos); ABB4(_3E
output.writeLong(fileSplitterFetch.nEndPos); r`VKb
} z1_\P) M
output.close(); BY72fy#e
} $ ^m_M.1
catch(IOException e){e.printStackTrace ();} JT,8/o
catch(Exception e){e.printStackTrace ();} KE6[u*\
} H/YZwDx,i
(+(YO\ng6
,J~kwJ$L
//读取保存的下载信息（文件指针位置） Tw);`&Ulo
private void read_nPos() PO]z'LD
{ M+9G^o)u
try{ o%5^dX&[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2t*@P"e!
int nCount = input.readInt(); do C8!
nStartPos = new long[nCount]; >kd&>)9v
nEndPos = new long[nCount]; R"VmN2
for(int i=0;i<nStartPos.length;i++) H5{d;L1[
{ SX$v&L<
nStartPos = input.readLong(); +QqYf1@F
nEndPos = input.readLong(); p.n+m[
} A9!%H6
input.close(); 7;+:J;xf66
} a3sXl+$D@
catch(IOException e){e.printStackTrace ();} a>G|t5w
catch(Exception e){e.printStackTrace ();} 6m|j "m
} Ft#d& I
[0w@0?[
`c ^2
private void processErrorCode(int nErrorCode) c4k3|=f
{ b<~\IPY
System.err.println("Error Code : " + nErrorCode); =6Ihk
} b7p&EK"Hm
t[XxLG*
]]J2#mN:n
//停止文件下载 U8PSJ0ny
public void siteStop() EQET:a:g
{ JFIUD{>fp
bStop = true; XL1v&'HLV
for(int i=0;i<nStartPos.length;i++) swntz
fileSplitterFetch.splitterStop(); 5\A[ra
_t_X`
mvyqCOp0
} VZ5EV'D8!
} j ~:Dr
//负责部分文件的抓取 CfNHv-jDL
**FileSplitterFetch.java rfpeX
*/ Gcna:w>6d
package NetFox; qe8dpI;
k,LeBCqGcb
1D sgU6"
import java.io.*; 7loIX Qw
import java.net.*; !'Q/9%g
s+8 v7ZJ
q["CT&0
public class FileSplitterFetch extends Thread { $*tq$DZ4&
%qfql
mx y>
String sURL; //File URL G'{$$+U^K
long nStartPos; //File Snippet Start Position mp:%k\cF|
long nEndPos; //File Snippet End Position A]id*RtY
int nThreadID; //Thread's ID *tC]Z&5
boolean bDownOver = false; //Downing is over ]L@VpHEj
boolean bStop = false; //Stop identical -^`]tF`M
FileAccessI fileAccessI = null; //File Access interface ,|,DXw
uW3`gwwlU
V\^3I7F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WLma)L`L
{ 9 ,=7Uh#7
this.sURL = sURL; ( 6|S42
this.nStartPos = nStart; XbsEO>_Z'A
this.nEndPos = nEnd; -K9bC3H
nThreadID = id; P,^`|\#7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E"ijNs
} 7{e0^V,\k
2>Bx/QF@<
K4b# y~@
public void run() %"Q{|}
{ y w)q3zC
while(nStartPos < nEndPos && !bStop) F:"<4hiA"
{ a;jXMR
2It$ bz
_h",,"p#o
try{ wg\*FfQn
URL url = new URL(sURL); yJkERiJV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |r[yMI|VR
httpConnection.setRequestProperty("User-Agent","NetFox"); 2UU5\ jV6
String sProperty = "bytes="+nStartPos+"-"; f0]8/)
httpConnection.setRequestProperty("RANGE",sProperty); _C$JO
Utility.log(sProperty); sS/#)/B
@.T(\Dq^
`OO=^.-u
InputStream input = httpConnection.getInputStream(); Bt[OGa(q
//logResponseHead(httpConnection); &(UVS0=Dp,
P~$FgAV
{h5 S=b
byte[] b = new byte[1024]; u4*7n-(
int nRead; l3dGe'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bU9B2'%E
{ ;gfY_MXnF
nStartPos += fileAccessI.write(b,0,nRead); /^v?Q9=Y
//if(nThreadID == 1) #-?pY"N,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o_>id^$>B
} a<9cj@h
WDc2Qt
5|&8MGW-$
Utility.log("Thread " + nThreadID + " is over!"); b37P[Q3
bDownOver = true; P[6@1
//nPos = fileAccessI.write (b,0,nRead); 6UOV,`:m+
} *$mDu,'8
catch(Exception e){e.printStackTrace ();} *)+1BYMo
} lX$6U|!
} 3#o!K
s\A"B#9r
F[uy'~;@
//打印回应的头信息 |y=;#A
public void logResponseHead(HttpURLConnection con) W!|A3V35\:
{ pcwkO
for(int i=1;;i++) R L&z\S
{ -7\Rl3c
String header=con.getHeaderFieldKey(i); SEsc"l8
if(header!=null) ckFnQhW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "X4L+]"$g
Utility.log(header+" : "+con.getHeaderField(header)); ~RGZY/4
else wmbjL=f Ia
break; yDh(4w-~gk
} e]R`B}vO
} \-3\lZ3qj
V9qZa
0T-y]&uo
public void splitterStop() mGR}hsQpn
{ }`M53>C,gQ
bStop = true; kNqSBzg
} 3NRxf8
mNS7/I\
o;bK 7D
} 3~ITvH,`s
JQ|qg\[
%HOMX{~}#
/* k{_ Op/k}V
**FileAccess.java .R5[bXxe7
*//文件访问(定位，写) dER#)bGj
package NetFox; z<2!|
import java.io.*; t}r`~AEa!
.XD7};g
pUtd_8
public class FileAccessI implements Serializable{ *PQu9>1w
v,z s dr"d
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0IU>KGJ-0s
RandomAccessFile oSavedFile; PAG.],"D
long nPos; 0?kaXD
wcz|Zy
pm$ZKM
public FileAccessI() throws IOException |tL57Wu93
{ tj:3R$a
this("",0); ANB@cK_
} \\;i
<s/n8#i=H
7d&_5Tj:
public FileAccessI(String sName,long nPos) throws IOException rUZRYF4C
{ <WXO].^
oSavedFile = new RandomAccessFile(sName,"rw"); U^jxKBq^
this.nPos = nPos; Cw`8[)=}o
oSavedFile.seek(nPos); )X*?M?~\
} p0Cp\.
`CCuwe<v
WmU5YZ(mAq
public synchronized int write(byte[] b,int nStart,int nLen) WXz'H),R
{ ;M,u,KH)/
int n = -1; C? pi8Xg
try{ VA4>!t)
oSavedFile.write(b,nStart,nLen); J[E_n;d1
n = nLen; {z)&=v@
} u{Jv6K,
catch(IOException e) /7WN,a
{ H:9Z.|{Gv
e.printStackTrace (); gp07I{0~m
} :|hFpLt
+B^(,qKMN
]L0GIVIE
return n; @oC# k<
} }6/L5j:+
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jG($:>3a@
} D(3\m)
jDI)iW`P
8#%Sq=/+M
/* Nxk3uF^
**SiteInfoBean.java zJ;K4)"j
*/ HQi57QB
package NetFox; >7@kwj-f)
$Pa7B]A,Ae
a*4"j2j v
public class SiteInfoBean { w)x`zVwO
3L2@C%
.Q'/e>0
private String sSiteURL; //Site's URL Wxjv=#3
private String sFilePath; //Saved File's Path en\shc{R]`
private String sFileName; //Saved File's Name z;Pr] *F
private int nSplitter; //Count of Splited Downloading File ]RYk Y7>`
nya-Io.
X4<!E#
public SiteInfoBean() U?/UW;k[
{//nSplitter的缺省值为5 +rEqE/QF
//default value of nSplitter is 5 -[-LR }u
this("","","",5); |Ad1/>8i
} piIr.]
3Cq/ o'
Izrf42 >k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "=~P&Mi_
{ Fy4jujP<
sSiteURL= sURL; -fF1vJ7L
sFilePath = sPath; [~&C6pR
sFileName = sName; npcB+6
this.nSplitter = nSpiltter; xEK+NKTeV
&tb
tCnx:1
} 99XbpP55
a }6Fj&hj
V>#iR>w_4,
public String getSSiteURL() NwQexYm1_
{ z-(#Mlq:!
return sSiteURL; .H1kl)~V
} wg6![Uh
Lo,z7"8
hK=\O)
public void setSSiteURL(String value) ESOuDD2<
{ q|PB[*T
sSiteURL = value; ]:* 8 Mb#
} n^QOGT.s6`
k;V4%O
@\gTi;u/x
public String getSFilePath() /EY^ui
{ XOl]s?6H$
return sFilePath; ; n2|pC^
} z1\G,mJK
Mwdh]I,#
.K![<eZ
public void setSFilePath(String value) /'|'3J]HP
{ m35Blg34
sFilePath = value; 5ug?'TOj'
} Q(lj&!?1k
|_l\.
>V~q`htth
public String getSFileName() }g WSV
{ U\S%Jq*
return sFileName; uM0!,~&9|
} \jn[kQ+pJ
<j1l&H|ux,
a,Gd\.D
public void setSFileName(String value) \Cx) ~bq<
{ '"}|'J
sFileName = value; < 4DWH
} Zl]Zy}p*+
w>I>9O}(`
]pLQ;7f7D
public int getNSplitter() cmDskQ:
{ E-,74B&H
return nSplitter; A.9,p
} H[o'j@0
&]~z-0`$!
@+",f]
public void setNSplitter(int nCount) ,x5`5mT3
{ sr\lz}JW
nSplitter = nCount; STgl{#
} Kb0OauW
} a/+tsbw
"s$v?voo
1Giy|;2/
/* L K9vvQz
**Utility.java 52B ye
*/ hCO*gtA)M
package NetFox; oS)0,p
zypZ3g{vz
gf+Kr02~
public class Utility { 5EIhCbA
^SCZ
`>RJ*_aKEI
public Utility() <\x/Y$jm0n
{ cHK)e2r
U{D ?1tF
F#_7mC
} JJ56d)37.
XF2u<sDe
//线程睡眠 &0TOJ:RP
public static void sleep(int nSecond) )8oI s
{ wgSA6mQZ
try{ ,_`\c7@
Thread.sleep(nSecond); KdFQlQaj
} @Z!leyam
catch(Exception e) zQxZR}'
{ AO;`k]0e
e.printStackTrace (); ZZTPAmIr
} _,b%t1v
} T3['6%
3y>.1
//日志 u*[,W-R&
public static void log(String sMsg) KtHh--j`
{ D_O%[u}
System.err.println(sMsg); I"3Qdi
} ?)Lktn9%
TJ`E/=J!
lfu1PCe5
public static void log(int sMsg) ^BjwPh4Z#
{ DVD}
System.err.println(sMsg); ~!]FF}6
} J{$C}8V
} !.L%kw7z
[7]p\'j
|LKhT4rE
/* }.gDaxj
**TestMethod.java ;: Hfkyy]
*/ {a_=4a
package NetFox; z>k6T4(
>0+m
133lIX+(k
public class TestMethod { {i^ ?XdM
yVQqz
`a:@[0r0U
public TestMethod() 2U>1-p&dn
{ ///xx/weblogic60b2_win.exe iUA2/ A
try{ >;o^qi_$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *P:`{ZV7=W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [x!T<jJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,{itnKJC
fileFetch.start(); DcoTa-~
} 3Q[]lFJ}F
catch(Exception e){e.printStackTrace ();} M O* m@
s;}';#
Mim 9C]h(
} e@p` -;<
hr@KWE`
'm}~
public static void main(String[] args) xm~ff+(&@S
{ M6AQ8~z
new TestMethod(); s\o </ZDo
} gbr|0h>
} S7wZCQe
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