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)); ~"-wSAm
} sB6UlX;b:
for(int i=0;i<nEndPos.length-1;i++) = *sP, 6
{ ,Zdc
nEndPos = nStartPos[i+1]; t~Uqsa>n@'
} {DpZg",H-
nEndPos[nEndPos.length-1] = nFileLength; i_MDLS>-
} NmeTp?)m
} A >x{\
os>|LPv4
9TF[uC)-2
//启动子线程 DI*xf Kt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8]0^OSS
for(int i=0;i<nStartPos.length;i++) rO-Tr
{ #hai3>9|B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hi?],5,/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E_h9y
nStartPos,nEndPos,i); cD{[rI E3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r6^DD$X
fileSplitterFetch.start(); 0c]Lm?&
} 6gp3n;D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IlwY5iL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E_xpq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mFvw s
nEndPos = " + nFileLength); `T-(g1:9
// fileSplitterFetch[nPos.length-1].start(); @A)gsDt9A
[p]Ayo$~
6Up,B=sX0
//等待子线程结束 w_9:gprf
//int count = 0; }g3)z%Xe'[
//是否结束while循环 ;1BbRnCr
boolean breakWhile = false; 4b4nFRnH
D3I;5m`_
<uA|nYpp
while(!bStop) Z!#zr@'k
{ d/;oNC+
write_nPos(); 7Npz {C{I
Utility.sleep(500); 39u!j|VH
breakWhile = true; #fa~^]EM]
gP<l
50CU|
for(int i=0;i<nStartPos.length;i++) N?~K9jGx(
{ ;X\!*Loe
if(!fileSplitterFetch.bDownOver) NxNz(R $~
{ )2\6Fy0S
breakWhile = false; N 4Dyec\
break; u%&zY97/
} &359tG0@P
} nkvzv
if(breakWhile) 6N]v9uXZ
break; ^oA^z1>3
pO"V9[p]
wKwireOs
//count++; |,qz7dpe
//if(count>4) C7PHZ`<
// siteStop(); 1(C%/g#"
} 8TuOf(qE
Z,ag5 w`]L
Lx2.E1?@
System.err.println("文件下载结束！"); Y(<>[8S m
} #A?U_32z/2
catch(Exception e){e.printStackTrace ();} a?@j`@]ZR~
} kRG-~'f%`
iX~V(~v
O"Ar3>
//获得文件长度 [_${N,1
public long getFileSize() #SQFI;zj
{ T#T!a0
int nFileLength = -1; w(s"r p}
try{ eRD s?n3F
URL url = new URL(siteInfoBean.getSSiteURL()); mw.9cDf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JgEpqA12
httpConnection.setRequestProperty("User-Agent","NetFox"); aWW|.#L
rlW
1J^{h5?lU
int responseCode=httpConnection.getResponseCode(); -p9|l%W
if(responseCode>=400) RzNv|
{ {V8v
processErrorCode(responseCode); ~GMlnA]6
return -2; //-2 represent access is error ~`T3 i
} \U,.!'+
Xa+ u>1"2"
Ao 1*a%-.
String sHeader; h@l5MH=|%
]Y:|%rvVH
Haiuf)a
for(int i=1;;i++) #m|AQr|
{ 6f0 WN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q;SMwCB0M
//Utility.log(in.readLine()); HJM-;C](
sHeader=httpConnection.getHeaderFieldKey(i); ]*Zg(YA
if(sHeader!=null) |UE&M3S
{ ,D>$N3;
if(sHeader.equals("Content-Length")) "<NQ2Vr]5
{ 5G=2=E
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 03[(dRK>=
break; :jgwp~l
} mM1\s>o
} D.4=4"qMi
else #~ UG9@a
break; 9 *Q/3|
} b4i=eI8
} PWx2<t<;9
catch(IOException e){e.printStackTrace ();} &`GQS|
catch(Exception e){e.printStackTrace ();} _=8x?fC:rl
*tO7A$LDT
nO2-fW:9]
Utility.log(nFileLength); V6Z2!Ht
C%0|o/Wi
<e)3 j6F!
return nFileLength; Q]A;VNx
} O$LvHv!
9psD"=/"
6O!&!
//保存下载信息（文件指针位置） ^.M*pe
private void write_nPos() /c8F]fkZ=
{ zuwCN.
try{ ~~]L!P
output = new DataOutputStream(new FileOutputStream(tmpFile)); PL[7|_%
output.writeInt(nStartPos.length); Zm^4p{I%o*
for(int i=0;i<nStartPos.length;i++) 8ZE{GX.m2c
{ S~/zBFo-
// output.writeLong(nPos); 2/x+7F}w5
output.writeLong(fileSplitterFetch.nStartPos); bwS1YGb
output.writeLong(fileSplitterFetch.nEndPos); :dLfM)8}
} 9#xcp/O
output.close(); E_MGejm@
} G(EiDo&
catch(IOException e){e.printStackTrace ();} xm6cn\e
catch(Exception e){e.printStackTrace ();} 8$BZbj%?hx
} ZV$qv=X
/T!S)FD\/v
O-@*xwD
//读取保存的下载信息（文件指针位置） '/J}T -,Z
private void read_nPos() a$l
{ %70sS].@
try{ )E'iC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g,@0 ;uVq
int nCount = input.readInt(); ;3-5U&Axt
nStartPos = new long[nCount]; Re0ma%~LP
nEndPos = new long[nCount]; *am.NH\
for(int i=0;i<nStartPos.length;i++) F$N"&<[c
{ ;|5m;x/a
nStartPos = input.readLong(); S9U,so?
nEndPos = input.readLong(); ]4ya$%A
} )#N)w5DU
input.close(); " +'E
} c~K^ooS-
catch(IOException e){e.printStackTrace ();} PTXy:>]M
catch(Exception e){e.printStackTrace ();} TLU^ad#9E
} ri<E[8\
1D sgU6"
7loIX Qw
private void processErrorCode(int nErrorCode) N=YRYUo
{ s+8 v7ZJ
System.err.println("Error Code : " + nErrorCode); q["CT&0
} <b~KR8
%qfql
mx y>
//停止文件下载 G'{$$+U^K
public void siteStop() mp:%k\cF|
{ A]id*RtY
bStop = true; *tC]Z&5
for(int i=0;i<nStartPos.length;i++) &.,ZU\`zT
fileSplitterFetch.splitterStop(); >jD,%yG
|W];8
o$8v8="p
} :UGc6
} &'uFy0d,
//负责部分文件的抓取 Pwn"!pk
**FileSplitterFetch.java NguJ[
*/ 0'{0kE[wn
package NetFox; - &Aw]+
wws)**]J8
&`[y]E'
import java.io.*; </3Shq
import java.net.*; ]([:"j
dh#4/Wa,
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public class FileSplitterFetch extends Thread { 8M9 &CsT6
j'Z};3y
eLXG _Qb"
String sURL; //File URL H|T!}M>
long nStartPos; //File Snippet Start Position I0trHrX9
long nEndPos; //File Snippet End Position G%_6"s
int nThreadID; //Thread's ID +P2f<~
boolean bDownOver = false; //Downing is over lS&$86Jo(
boolean bStop = false; //Stop identical 0*o)k6?q3
FileAccessI fileAccessI = null; //File Access interface 2iYf)MC
UE^_SZ
tkx1iBW=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~$-Nl
{ 5RCZv\Wd&
this.sURL = sURL; c+|,qm
this.nStartPos = nStart; Hg\+:}k&9
this.nEndPos = nEnd; AQ:cim`
nThreadID = id; $R4[TQY).!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :SjTkfU
} ;$gZ?&
0vbiq
#K:|@d
public void run() `@eo <6
{ P{v>o,a.
while(nStartPos < nEndPos && !bStop) ;`Eie2y{M
{ !g{9]"Z1T
f|G,pDLx
<8nl}^d5
try{ FjYih>
URL url = new URL(sURL); %y;E1pva
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7714}%Z
httpConnection.setRequestProperty("User-Agent","NetFox"); Ta^l1]9.*
String sProperty = "bytes="+nStartPos+"-"; chv0\k"'
httpConnection.setRequestProperty("RANGE",sProperty); Cg[]y1Ne
Utility.log(sProperty); ~=qJSb
""Nu["|E
U+gOojRy{
InputStream input = httpConnection.getInputStream(); ,&[2z!
//logResponseHead(httpConnection); d:jD
ihivJZ
*<?or"P
byte[] b = new byte[1024]; $K1 /^
int nRead; R?@F%J;tx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *ILx-D5qr
{ J`}5bnFP
nStartPos += fileAccessI.write(b,0,nRead); ZS[(r-)$F
//if(nThreadID == 1) rV.04m,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 04>dxw)8
} <$!^LKKzA
!pY=\vK;
7 \)OWp
Utility.log("Thread " + nThreadID + " is over!"); ej-x^G?C
bDownOver = true; foY=?mbL
//nPos = fileAccessI.write (b,0,nRead); c^0YuBps[
} kNqSBzg
catch(Exception e){e.printStackTrace ();} {?tK]g#
} mNS7/I\
} o;bK 7D
3~ITvH,`s
JQ|qg\[
//打印回应的头信息 %HOMX{~}#
public void logResponseHead(HttpURLConnection con) k{_ Op/k}V
{ ue8Cpn^M
for(int i=1;;i++) z*?-*6W
{ $OOZ-+8
String header=con.getHeaderFieldKey(i); vpR^G`/
if(header!=null) $t.i)wg +
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^3B)i=
Utility.log(header+" : "+con.getHeaderField(header)); &<8Q/m]5
else F^& Rg
break; <X9 T}g
} {.c(Sw}Eo
} *h6Lh]7
g}HB|$P7
F&?55@b
public void splitterStop() {B^V_TX2
{ u%n6!Zx
bStop = true; 9+<%74|,
} $B6CLWB
.Y B}w
HsrIw
} c"qaULY
E+wd9/;
f4.k%|]
/* lR]z8&
**FileAccess.java g$C-G5/bjD
*//文件访问(定位，写) D5]4(]k&
package NetFox; F\&Sn1>k
import java.io.*; =2&/Cn4
VxD_:USIF
C'8v\C9Ag
public class FileAccessI implements Serializable{ Da_8Q(XFe
2uonT,W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %jaB>4.A:
RandomAccessFile oSavedFile; p<>xqU
long nPos; jtqH3xfy
e1Kxqw7
"-aak )7w
public FileAccessI() throws IOException m\a_0!K
{ 0Y rdu,c
this("",0); RiHOX&-7
} Wn;B~
a^yBtb~,P
lZT9 SDtS
public FileAccessI(String sName,long nPos) throws IOException h{zE;!+)D
{ /Mk85C79
oSavedFile = new RandomAccessFile(sName,"rw"); @**@W[EM
this.nPos = nPos; a& >(*PQ
oSavedFile.seek(nPos); Z4YQ5O5
} >~O36q^w
hw[jVx
v(ABZNIn
public synchronized int write(byte[] b,int nStart,int nLen) Nda,G++5(
{ $@m)8T
int n = -1; ;8WgbR)ZLU
try{ ,(aOTFQS
oSavedFile.write(b,nStart,nLen); 7U=|>)Q0s
n = nLen; G9?6qb:
} kOfq6[JC
catch(IOException e) ?f1PQ
{ *69yB
e.printStackTrace (); /8!s C D
} cG|)z<Z
\BB(0Ah+t
M6(oJ*
return n; +uR|0Jo8X
} Z4S0{:XY
eIVCg-l}
X8!=Xjl)
} Z2z"K<Z W
7%rSo^t,L
a'R)3:S
/* Q_}i8p'
**SiteInfoBean.java cG%ttfq\
*/ V,,/}f'
package NetFox; )9_jr(s
&cj/8A5-
_n9+(X3
public class SiteInfoBean { y'sy]Q~
$`q8-+{
\Y'#}J"dh
private String sSiteURL; //Site's URL e|wH5(V
private String sFilePath; //Saved File's Path z4l O
private String sFileName; //Saved File's Name T';<;6J**
private int nSplitter; //Count of Splited Downloading File c*nH=
+ -e8MvP
tPO\e]
public SiteInfoBean() 1$,t:/'-4
{//nSplitter的缺省值为5 gI^);JrTE
//default value of nSplitter is 5 M1._{Jw5
this("","","",5); nquKeH
} *SkUkqP9z
gv=mz,z
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6bL+q`3>
{ z1\G,mJK
sSiteURL= sURL; Mwdh]I,#
sFilePath = sPath; .K![<eZ
sFileName = sName; /'|'3J]HP
this.nSplitter = nSpiltter; m35Blg34
4}{S8fGk%
MFHPh8P
} }g WSV
U\S%Jq*
?p{xt$<p
public String getSSiteURL() 0x'-\)v>3
{ <j1l&H|ux,
return sSiteURL; %hK?\Pg3=E
} gi`K^L=C
4XL*e+UfJ
]2n&DJu
public void setSSiteURL(String value) Hfer\+RX
{ ^G63GYh]y
sSiteURL = value; .%+`e
} o/I<)sa
fShf4G_w\
')#E,Y%Hq
public String getSFilePath() dfB#+wh
{ T:0X-U
return sFilePath; m:TS .@p
} bhXH<=
U*8;ZXi
?WWnt^
public void setSFilePath(String value) R7us9qM4e
{ %hU8ycI*h
sFilePath = value; 7BCCQsz<
} /'1UfjW>
b2 ~~!C
y(|6`
public String getSFileName() Gy[;yLnX
{ $Aww5G5e
return sFileName; 8k'UEf`'(
} Z,o*M#}
woZ'T
GY4:9Lub7
public void setSFileName(String value) p7(xk6W
{ Ty%4#9``0
sFileName = value; (]0$^!YK
} R!xs;|]
)!MeSWGq
L@?Dmn'v
public int getNSplitter() HZ=Dd4!
{ BQf}S +
return nSplitter; 87EI<\mP
} );$Uf!v4
'{kNXCnZ
pTZPOv#?Q
public void setNSplitter(int nCount) 0CY_nn#3
{ "ffwh
nSplitter = nCount; E66e4?"
} P,!W\N%3
} ?/"@WP9
+SM $#
io cr
/* ro37H2^Ty
**Utility.java xkl'Y*
*/ \Ja%u"DA
package NetFox; e =& abu
ld94ek
7"=
public class Utility { D@qq=M
]M{SM`Ya
2uw%0r3Vi6
public Utility() n4)G g~PE
{ #e&j]Q$Eh
N`y!Km
\~xsBPX+x
} p<'mc|hGq
g=pz&cz;>\
//线程睡眠 tjOfekU
public static void sleep(int nSecond) $c0SWz
{ HhNH"b&
try{ k(\HAIW
Thread.sleep(nSecond); IGql^,b
} U*/
catch(Exception e) r0QjCFSF=
{ FqsG#6|x
e.printStackTrace (); ]*}*zXN/E
} X=(8t2
} Pf)<6?T
VYf$0oo\4
//日志 &X_I^*
public static void log(String sMsg) ZERUvk
{ ({![
System.err.println(sMsg); PK3)M'[
} ci5ERv`
2DTH|Yv
yt C{,g>
public static void log(int sMsg) dz5bW>
{ -J!F((jt
System.err.println(sMsg); ]*juF[r(
} B/E1nBobC
} D8h?s
}<FBcc(n
S7wZCQe
/* D.qbzJz
**TestMethod.java S3hJL:3c
*/ F#4?@W
package NetFox; ?Pl>sCFm~
&Z=}H0y q
o'myo.k{
public class TestMethod { *v:+AE
}?*:uf
L7n->8Qk
public TestMethod() &z{oVU+mA
{ ///xx/weblogic60b2_win.exe lhQ*;dMj%"
try{ aChY5R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lqqY5l6j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ReKnvF~
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8XX,(k_b
fileFetch.start(); K"Nq_Ddwd
} }'kk}2ej`
catch(Exception e){e.printStackTrace ();} #k)G1Y[c
.eZ4?|at.F
OD>-^W t;%
} ; {I{X}b
`Up<;
JEY%(UR8
public static void main(String[] args) sF_.9G)S0
{ "TtK!>!.
new TestMethod(); Gpe h#Q4x
} QHMXQyr(
} ~DqNA%Mb
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