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)); xg'z_W
} ME1lQ7E4B
for(int i=0;i<nEndPos.length-1;i++) iquB]z'
{ "a-Ex ]
nEndPos = nStartPos[i+1]; jio1#&
} p(%7|'
nEndPos[nEndPos.length-1] = nFileLength; RqXcL,,9
} vd SV6p.d
} 4<70mUnt
>;nE.]
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//启动子线程 uezqC=v$h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mmAikT#k
for(int i=0;i<nStartPos.length;i++) Vur$t^zE
{ ,`G8U/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %U)/>Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $91c9z;f^
nStartPos,nEndPos,i); D.j'n-yw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p<'#f,o
fileSplitterFetch.start(); RhnSQe
} m7^aa@^m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z;GnQfYG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $=4T# W=m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nu}$wLM
nEndPos = " + nFileLength); PNd]Xmv)
// fileSplitterFetch[nPos.length-1].start(); O!lZ%j@%
<O?iJ=$
m-dne/%_
//等待子线程结束 +e`f|OQ
//int count = 0; Iujly f
//是否结束while循环 .rD@Q{e50
boolean breakWhile = false; jB:$+k|~.
*.ri8
X7?p$!M6;B
while(!bStop) :qc@S&v@]
{ U GQ{QH
write_nPos(); {%9)l,
Utility.sleep(500); vmvk
breakWhile = true; m7zen530
hewX)
x %L2eXL
for(int i=0;i<nStartPos.length;i++) U voX\
{ GX&BUP\
if(!fileSplitterFetch.bDownOver) -f#0$Z/0
{ "8&pT^
breakWhile = false; 7!#x-KR~5
break; 0_}OKn)J
} (\, <RC\
} BZ">N
if(breakWhile) @R_a'v-
break; sk\U[#ohH
1%]|O
%UI.E=`n
//count++; Lz2wOB1Zc+
//if(count>4) EQSOEf[
// siteStop(); ,@tkL!"9q
} iN"kv
II3)Cz}xRG
$/Gvz)M
System.err.println("文件下载结束！"); BDNn~aU#m
} P_B#
catch(Exception e){e.printStackTrace ();} 6B)(kPW
} ~.u}v~ F
9 #TzW9
B&Q\J>l9S
//获得文件长度 !lKO|Y
public long getFileSize() ]iRE^o6
{ bTHKMaGWC
int nFileLength = -1; c$rkbbf~V
try{ dQYb)4ir
URL url = new URL(siteInfoBean.getSSiteURL()); ^ ~:f02[D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wdS^`nz|
httpConnection.setRequestProperty("User-Agent","NetFox"); );_g2=:#
{(w/_C9
+(x^5~QX
int responseCode=httpConnection.getResponseCode(); O%H_._#N`
if(responseCode>=400) l)[\TD
{ n1 =B
processErrorCode(responseCode); T1m"1Q
return -2; //-2 represent access is error QM2Y?."#
} n.ZLR=P4
8i!AJF9IQ}
L{jJDd
String sHeader; E0'+]"B
=@AWw:!:,
V&;1n
for(int i=1;;i++) L3JFQc/oh~
{ Yz=(zj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rdhK&5x*
//Utility.log(in.readLine()); onRxe\?D(
sHeader=httpConnection.getHeaderFieldKey(i); _Db=I3.HJ
if(sHeader!=null) CL.JalR`b
{ <vJPKQ`=:
if(sHeader.equals("Content-Length")) K*&M:u6E
{ seC]=UJh#>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eqU2>bIf
break; 0vuL(W8)
} RbzSQr>a\
} I|9(*tq)
else G#gUd'=M
break; lYmqFd~p
} -$**/~0zU
} @X4Ur+d
catch(IOException e){e.printStackTrace ();} AD#]PSB
catch(Exception e){e.printStackTrace ();} V>ML-s9
'9c`[^
GL[#XB>n
Utility.log(nFileLength); gKeqf-UWKJ
g6{.C7m
.<`i!Ls
return nFileLength; M(|Qvh{Q6
} v".q578 0B
1j0OV9-|
4e~^G
//保存下载信息（文件指针位置） T]Z|Wq`bot
private void write_nPos() s:3 altv
{ #"-?+F=rk
try{ 5Ds/^fA
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0D/u`-
output.writeInt(nStartPos.length); (|)`~z
for(int i=0;i<nStartPos.length;i++) c[\ :^w^I6
{ 4YDK`:4I~
// output.writeLong(nPos); ~XN--4%Q
output.writeLong(fileSplitterFetch.nStartPos); =}>wxO
output.writeLong(fileSplitterFetch.nEndPos); uPKq<hBI
} <_$]!Z6UR
output.close(); ?j;e/r.
} (MhC83|?
catch(IOException e){e.printStackTrace ();} &IsQgS7R
catch(Exception e){e.printStackTrace ();} =M'M/vKD
} PLU8:H@X
nlmc/1C
bP\0S@1YL
//读取保存的下载信息（文件指针位置） A'r 3%mC
private void read_nPos() E9z^#@s
{ =y-L'z&r
try{ M4 SJnE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Cw42bO
int nCount = input.readInt(); 7K.&zn
nStartPos = new long[nCount]; J!5BH2bg
nEndPos = new long[nCount]; %|E'cdvkX
for(int i=0;i<nStartPos.length;i++) _Z?{&k
{ @)PA9P |
nStartPos = input.readLong(); u$ C@0d
nEndPos = input.readLong(); =sy>_
} 56gpAc
input.close(); U"$Q$ OFs
} Ck;O59A"&-
catch(IOException e){e.printStackTrace ();} 7?Q@Hj(:NT
catch(Exception e){e.printStackTrace ();} o#3?")>|
} y_EkW f
uw!
IN=pki|.
private void processErrorCode(int nErrorCode) VH[r@Pn
{ BCsz8U!
System.err.println("Error Code : " + nErrorCode); MJNY#v3
} d]1%/$v^
2{;&c
J$6h%Eyo
//停止文件下载 AQn>K{M
public void siteStop() :*bv(~FW
{ %x@ D i`;
bStop = true; >dKK [E/[d
for(int i=0;i<nStartPos.length;i++) b~DtaGh
fileSplitterFetch.splitterStop(); [ []'U'
0^'A^
u.;zz'|
} ^kZfE"iE2
} "<o[X ?u
//负责部分文件的抓取 M S 3?#b
**FileSplitterFetch.java +Go(yS
*/ 2VmQ%y6e"
package NetFox; =B4,H=7Spf
HUqG)t*c1
Oop5bg
import java.io.*; VD[x}8ei
import java.net.*; <!b~7sZkTc
}$M 2XF
'=MaO@ @
public class FileSplitterFetch extends Thread { fxfzi{}uj
r@C2zF7
,XT#V\qne
String sURL; //File URL u8ofgcFYE
long nStartPos; //File Snippet Start Position ^0"^Xk*
long nEndPos; //File Snippet End Position T}} 0hs;
int nThreadID; //Thread's ID N]n]7(e+0C
boolean bDownOver = false; //Downing is over i9Fg
boolean bStop = false; //Stop identical Q'-V\G)11
FileAccessI fileAccessI = null; //File Access interface VBc[(8o
eduaG,+k7p
O7@CAr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Eu/~4:XN
{ 6k6M&a
this.sURL = sURL; / hUuQDJ
this.nStartPos = nStart; 5G.Fi21 b
this.nEndPos = nEnd; Bz}Dgbb
nThreadID = id; 5 o:VixZf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C${{&$&
} DxjD/?R8
JQ{g'cT
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public void run() rM<lPMr1*
{ Bvzu{B%
while(nStartPos < nEndPos && !bStop) >55c{|"@L
{ a<X8l^Ln
tX;00g;U.
4d&#NP
try{ {FzL@!||
URL url = new URL(sURL); Ol,;BZHc\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 36>pa
httpConnection.setRequestProperty("User-Agent","NetFox"); xdWfrm$;ZA
String sProperty = "bytes="+nStartPos+"-"; (Wkli:Lq
httpConnection.setRequestProperty("RANGE",sProperty); 2 qRXA
Utility.log(sProperty); Y" 9 o
rkhQoYZ[
dz/' m7
InputStream input = httpConnection.getInputStream(); <hi@$.u_Q^
//logResponseHead(httpConnection); 1-Fg_G}|6
Hw"ik6
B5J!&suX
byte[] b = new byte[1024]; jvx9b([<sG
int nRead; J6x\_]1:*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 216+ tX5Z
{ M=[/v/M=
nStartPos += fileAccessI.write(b,0,nRead); 2m.RM&TdB
//if(nThreadID == 1) H <CsB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @rs(`4QEh
} R"(rL5j
Z=%+U _,
?fv?6r
Utility.log("Thread " + nThreadID + " is over!"); qGMM3a)Q
bDownOver = true; ';`fMcN
//nPos = fileAccessI.write (b,0,nRead); Ke-Q>sm2Q
} M0!;{1
catch(Exception e){e.printStackTrace ();} +3.Ik,Z}zq
} N[4v6GS
} }HS:3Dt
?]gZg[
@C)O[&Sk
//打印回应的头信息 lhg3 }dW
public void logResponseHead(HttpURLConnection con) T!$7:% D
{ zb9^ii$g
for(int i=1;;i++) jB }O6u[%
{ #1R_* Uh
String header=con.getHeaderFieldKey(i); }aYm86C]
if(header!=null) 9@AGx<S1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %VYQz)yW
Utility.log(header+" : "+con.getHeaderField(header)); G)gf +)W
else A(duUl~
break; `}o4&$
} ~^/zCPy[w
} J5LP#o(V
$mm =$.
n+@}8;oeP
public void splitterStop() g+/%r91hZ
{ !- f>*|@
bStop = true; lJ]r%YlF
} !f_GR Pj'
P# 2&?.d\
2=ZR}8}9Q:
} Z+ubc"MVb
Cus=UzL
m%V+px
/* 2{s ND
**FileAccess.java J<DV7zV
*//文件访问(定位，写) b~06-dk1
package NetFox; ulFU(%&
import java.io.*; o;Ijv\Em
4W8rb'B!Ay
ANSvZqKh
public class FileAccessI implements Serializable{ 9[DQ[bL
nPq\J~M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~\dpD
RandomAccessFile oSavedFile; >_M}l@1
long nPos; LLmgk"
tW5\Ktjno
a:@9GmtV&
public FileAccessI() throws IOException vy/U""w`
{ kF'^!Hp
this("",0); #1Mk9sxo
} EZ #UdK_
Y0BvN`E
hM E|=\
public FileAccessI(String sName,long nPos) throws IOException :b>Z|7g?
{ Wq)'0U;{$
oSavedFile = new RandomAccessFile(sName,"rw"); A{h hnrr8
this.nPos = nPos; , >Y.!
oSavedFile.seek(nPos); _yjM_ALjo
} L*tXy>&b.
kN9S;o@)
X@+:O-$
public synchronized int write(byte[] b,int nStart,int nLen) &n<jpMB
{ rP ;~<IxEr
int n = -1; (Wr;:3i
try{ Y^LFJB|b4
oSavedFile.write(b,nStart,nLen); ->wY|7
n = nLen; ;]fpdu{
} hgj#VY$B
catch(IOException e) j>&n5?
{ [2w3c4K
e.printStackTrace (); y- k?_$M
} 7^sU/3z
WAY<X:|We
&ukNzV}VW
return n; GQqw(2Ub}
} !N$4.slr<p
=D5@PHpv(
=khjD[muC
} 3FUZTX]Q1
$Br^c< y
~p;<H
/* {EJVZG:&
**SiteInfoBean.java *B}vYX
*/ :'y
package NetFox; |UnTd$m
?f']*pD8
\!ESmxSa;
public class SiteInfoBean { y NV$IN%
?Z4&j'z<
};9dd3X
private String sSiteURL; //Site's URL %W"\
private String sFilePath; //Saved File's Path PkDL\Nqe
private String sFileName; //Saved File's Name x|0Q\<mEe
private int nSplitter; //Count of Splited Downloading File u4VQx,,
]&/jvA=\l,
ibzYY"D:
public SiteInfoBean() rShi"Yw
{//nSplitter的缺省值为5 *(?YgV
//default value of nSplitter is 5 O#O~A|
this("","","",5); #a#~YSnG
} "EEE09~l\
b]RCe^E1
344,mnAd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j,/o0k,
{ W\.f:"2qr
sSiteURL= sURL; 8YkP57Y%[Z
sFilePath = sPath; 74gU4T
sFileName = sName; H'gPGOd
this.nSplitter = nSpiltter; lG#&Pv>-
K'?ab 0
bG^eP:r
} Jr17pu(t
4n3QW%#
2IjqTL
public String getSSiteURL() hN\E8"To
{ w41#?VC/
return sSiteURL; hph 3kfR
} Jq6p5jr"
W[^XG\
ac+7D:X
public void setSSiteURL(String value) +Yi=Wo/
{ oeIB1DaI
sSiteURL = value; XQj`KUO@
} 4] ?
oPa2GW8
*qOo,e
public String getSFilePath() Ix:aHl
{ d0-}Xl
return sFilePath; pbqa
} =1yUH9\,b
BOwkC;Q[
~Ag!wj
public void setSFilePath(String value) Q]6nW[@j'
{ ?'T>/<(
sFilePath = value; $Fr2oSTT)
} M8juab%y
rcI(6P<*
;uoH+`pf
public String getSFileName() K?I@'B'
{ "#4PU5.
return sFileName; -D!F|&$
} I*lq0&
boN)C?"^h
*[.\S3K`
public void setSFileName(String value) 6Ir ?@O1'!
{ T$}<So|
sFileName = value; 42m`7uQ
} 8 6L&u:o:
h)y"?Jj
:hMuxHr
public int getNSplitter() /_}v|E0
{ H>M%5bj
return nSplitter; R1P,0Yf
} tOspDPSXX
$u3N',&
4uNcp0
public void setNSplitter(int nCount) k ,<L#?,a
{ 0.@/I}R[
nSplitter = nCount; #h r!7Kc;N
} U Ciq'^,
} 1]hMA\x
)3..7ht3^5
<CA lJ
/* PKjA@+
**Utility.java !/jx4w~R
*/ \!SC;
package NetFox; (9cIU2e
r`S]`&#}(
j ^_G
public class Utility { 2iH,U
.5dZaI)
@Rx/]wyH
public Utility() K/%aoTO}
{ QGshc
Upv2s:wa}z
C62<pLJf
} .Zwn{SMtu
Np/[MC
//线程睡眠 iOJgZuP
public static void sleep(int nSecond) }VFSF/\^
{ c89RuI `B~
try{ 5mFi)0={y
Thread.sleep(nSecond); :_e.ch:4
} ax3:rl
catch(Exception e) Q]|+Y0y}X
{ .qVdo+M%F
e.printStackTrace (); VWMCbg>R
} LZoth+:
} x%(!+
G+%ZN
//日志 M.IV{gj
public static void log(String sMsg) Lqch~@E&%#
{ . }=;]=
System.err.println(sMsg); Jx{,x-I
} X,OxvmDm
_X]?
|/<iydP
public static void log(int sMsg) m.^6ef
{ aoJ&< vl3
System.err.println(sMsg); {;-$;\D
} 3[e@mcO
} d->b9
UWusSi3+LG
gq0gr?
/* V!Joh5=a
**TestMethod.java +'KM~c?]
*/ SjJUhTb
package NetFox; |QzPY8B9O
B[$SA-ZHi
Lte\;Se.tu
public class TestMethod { qh&K{r*T
6Edqg
QU#/(N(U#T
public TestMethod() '8Gw{&&
{ ///xx/weblogic60b2_win.exe snK9']WXo
try{ H~$|y9>qI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #`W8-w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); my} P\r.
SiteFileFetch fileFetch = new SiteFileFetch(bean); -#i%4[v
fileFetch.start(); 3{_+dE"9
} G6J3F
catch(Exception e){e.printStackTrace ();} ILVbbC`D
.6'T;SoK>
J`V6zGgW
} 1U9iNki
UG!&n@R
;{ezK8FJ}@
public static void main(String[] args) :5Vu.\,1
{ s e1ipn_A
new TestMethod(); _E"[%
} ?Z!KV=
} I3L1|!
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