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)); X{iidTW`xv
} @ev^e!B
for(int i=0;i<nEndPos.length-1;i++) +&*>FeJY
{ a YY1*^
nEndPos = nStartPos[i+1]; u4xJ-Vu
} lUiO|
nEndPos[nEndPos.length-1] = nFileLength; `FK qVd
} eGUe#(I /
} 'cY@Dqg1
9y*(SDF
+A%zFF3
//启动子线程 *7qa]i^]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )O\l3h"
for(int i=0;i<nStartPos.length;i++) +B7UGI
{ =H"%{VeC5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &VxK AQMxN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2|`~3B)#
nStartPos,nEndPos,i); KF7d`bRe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PAiVUGp5[
fileSplitterFetch.start(); LNvkC4
} R(2MI}T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T{ lm z<g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^.M_1$-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w_YY~Af
nEndPos = " + nFileLength); nZ`=Up p)
// fileSplitterFetch[nPos.length-1].start(); z.W1Za
7KtgR=-Lb
4-\4G"4
//等待子线程结束 /sVmQqVY
//int count = 0; K,*IfHi6[
//是否结束while循环 k,y#|bf,Y
boolean breakWhile = false; ">s0B5F7
kEg~yN
:0Fwaw9PH"
while(!bStop) lb]k"L%KU7
{ Lya?b
write_nPos(); ^fM=|.?
Utility.sleep(500); 5d|+c<
breakWhile = true; "H{#ib_c_
`~@}f"c`u
}J=zO8OL
for(int i=0;i<nStartPos.length;i++) }Ub "Vb
{ n4zns,:)/
if(!fileSplitterFetch.bDownOver) os(}X(
{ /`w'X/'VJ
breakWhile = false; -Q!?=JNtQ
break; n4 Y ]v
} }Z`@Z'
} 4;w#mzd
if(breakWhile) _xdttO^N
break; ;~s@_}&
U7G|4(
!" : arK
//count++; 1xwq:vFC.
//if(count>4) *OZO} i
// siteStop(); \g|;7&%l3
} YGLR%PYv"
b$FXRR\G
F,XJGD*
System.err.println("文件下载结束！"); 9a.[>4}
} td+[Na0d
catch(Exception e){e.printStackTrace ();} 5gPAX $jH
} 4_S%K&
Zn'y"@%t[
T0}P 'q
//获得文件长度 ~0n9In%
public long getFileSize() !i6 aA1'
{ ::8E?c
int nFileLength = -1; CY9`HQ1
try{ Fw;Y)y=O
URL url = new URL(siteInfoBean.getSSiteURL()); ..^,*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k_Edug~B
httpConnection.setRequestProperty("User-Agent","NetFox"); dk2o>jI4;
SiJX5ydz
q}5&B=2pM
int responseCode=httpConnection.getResponseCode(); PiIILX{DuH
if(responseCode>=400) 0M>%1*
{ lc0ZfC
processErrorCode(responseCode); o6;VrpaNi
return -2; //-2 represent access is error GG_A'eX:I
} ?Qs>L~
YCQ+9
#D!3a%u0
String sHeader; fI0L\^b%
F[OBPPQ3
i@d@~M7/
for(int i=1;;i++) hO:X\:G
{ e3>k"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YuDNm}r[
//Utility.log(in.readLine()); ts0K"xmY\c
sHeader=httpConnection.getHeaderFieldKey(i); RbNRBK!{
if(sHeader!=null) d_Vwjv&@/"
{ ({x<!5XL
if(sHeader.equals("Content-Length")) w@2LFDp
{ QfM*K.7Sl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %x7l`.)N
break; ? 5 V-D8k
} `24:Eg6r
} N,_ej@L8
else yc5n
break; -.WVuc`
} `+/[0B=.
} h Tn^:%(
catch(IOException e){e.printStackTrace ();} )O%lh 8fI
catch(Exception e){e.printStackTrace ();} 9uREbip
u]cnbm
3/@'tLtN
Utility.log(nFileLength); )u&_}6z
9~mi[l~
`0Q:d'
return nFileLength; 7+u%]D!
} ;7<a0HZ5!
j|(bDa4\
ArU>./)Q
//保存下载信息（文件指针位置） BmUzsfD
private void write_nPos() Xc5[d`]
{ :<IW'
try{ ikRIL2Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); |,&!Q$<un
output.writeInt(nStartPos.length); RN:#+S(8
for(int i=0;i<nStartPos.length;i++) *id|za|:k
{ {UZli[W1
// output.writeLong(nPos); h?YjG^'9
output.writeLong(fileSplitterFetch.nStartPos); TJ5{Ee GV
output.writeLong(fileSplitterFetch.nEndPos); A?|cJ"N
} :7>Si%
output.close(); [I4FU7mpH
} MgMLfgt"V
catch(IOException e){e.printStackTrace ();} 7<^D7
catch(Exception e){e.printStackTrace ();} KwQO,($,]
} )SUN+YV^
Q84KU8?d
W{m0z+N[B
//读取保存的下载信息（文件指针位置） N<>dg
private void read_nPos() O x$|ZEh
{ =3SL& :8
try{ 83l)o$S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z#o\9/{(R
int nCount = input.readInt(); iK%Rq
nStartPos = new long[nCount]; X0Oq lAw
nEndPos = new long[nCount]; )Y&De)=
for(int i=0;i<nStartPos.length;i++) EJtU(HmW
{ BtHvfoT
nStartPos = input.readLong(); e<^4F%jSK
nEndPos = input.readLong(); kyo ,yD
} V!U[N.&$
input.close(); lIFU7g
} A^p $~e\)
catch(IOException e){e.printStackTrace ();} wD,F=O
catch(Exception e){e.printStackTrace ();} WNYLQ=;
} }C&c=3V
(kuZS4Af
My`%gP~%g
private void processErrorCode(int nErrorCode) P/PS(`
{ (&nl}_`7?,
System.err.println("Error Code : " + nErrorCode); S~Hj. d4/
} 0\~Zg
=W|Q0|U
: }IS=A
//停止文件下载 sTqB%$K}
public void siteStop() "DN`@
{ 3CHte*NL=
bStop = true; QF>[cdl?8
for(int i=0;i<nStartPos.length;i++) BVNh>^W5B
fileSplitterFetch.splitterStop(); Nb9pdkf0
x+TNF>%'D
3z#;0n}
} u ?Xku8 1l
} zn~m;0Xi
//负责部分文件的抓取 v1lj/A
**FileSplitterFetch.java P%lLKSA
*/ T?ZMmUE
package NetFox; 6e*b;{d
/(0d{
E37@BfpO3
import java.io.*; &L?Dogo
import java.net.*; &sRJ'oc
\~H"!vj
d#tUG~jc
public class FileSplitterFetch extends Thread { M:SxAo-D2
'} kq@
;i#gk%- 2
String sURL; //File URL ^,5.vfES
long nStartPos; //File Snippet Start Position ^9RBG#ud
long nEndPos; //File Snippet End Position g0U ?s
int nThreadID; //Thread's ID z} \9/`
boolean bDownOver = false; //Downing is over rN~`4mZ
boolean bStop = false; //Stop identical By_Ui6:D
FileAccessI fileAccessI = null; //File Access interface e.GzGX
DRIv<=Bt
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J?<L8;$s7
{ j&pgq2Kl
this.sURL = sURL; .2P?1HpK
this.nStartPos = nStart; E)E!
this.nEndPos = nEnd; Ttj5%~
nThreadID = id; 'x0t, ;g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !!86Sv
} I{PN6bn{>
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^hgAgP{{
public void run() Dn3~8
{ @ih}x
while(nStartPos < nEndPos && !bStop) $g};u[y
{ #50)DwD
8(D}y\
7. .vaq#
try{ K0g:Q*J-
URL url = new URL(sURL); j5O*H_D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~-GDheA
httpConnection.setRequestProperty("User-Agent","NetFox"); 3$cF)5Vf
String sProperty = "bytes="+nStartPos+"-"; -DnK)u\@
httpConnection.setRequestProperty("RANGE",sProperty); hrD6r=JT<~
Utility.log(sProperty); q':wSu u
<.B s`P
8TPm[r]
InputStream input = httpConnection.getInputStream(); KIFx&A
//logResponseHead(httpConnection); ]EnaZWyO]
PpRO7(<cD
o4;Nb|kk9+
byte[] b = new byte[1024]; 2~DPq p[
int nRead; 0mh8.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FudD
{ GvOAs-$
nStartPos += fileAccessI.write(b,0,nRead); QO.gt*"
//if(nThreadID == 1) $rEd5W&d!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jZ!JXmVV
} eLny-.i,7
0Y2^}u@5
[BBKj)IK
Utility.log("Thread " + nThreadID + " is over!"); F/SsiUBS
bDownOver = true; Cpcd`y=IN
//nPos = fileAccessI.write (b,0,nRead); YoJ'=z,e
} { NJ>[mKg
catch(Exception e){e.printStackTrace ();} 9VE;I:NO3
} H@ms43v\
} Dj+Osh
&>l8SlC?
ef;L|b%pp
//打印回应的头信息 N{t:%[
public void logResponseHead(HttpURLConnection con) i_Z5SMZ
{ Xh"iP%
for(int i=1;;i++) n;-r W;ZO
{ _%vqBr*
String header=con.getHeaderFieldKey(i); +[/r^C
if(header!=null) NCFV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ON0+:`3\
Utility.log(header+" : "+con.getHeaderField(header)); Q;/F0JDH
else Ch9!AUiR
break; Te}yQ=+
} !u}3H|6~
} J*!:ar
FT>~ES]cQd
je4&'vyU
public void splitterStop() \_AEuz3 F
{ x,gE$dNzy
bStop = true; u^zitW!X$
} 4E\ntufo
JlQT5k
~<- ci
} V?59.TJ
uyt-q|83=
:wZ`>,K"t>
/* o`mIi
**FileAccess.java hO.G'q$V
*//文件访问(定位，写) qd~98FS
package NetFox; YG~ o
import java.io.*; #pQ"+X
Df~p'N-$
1`]IU_)1B
public class FileAccessI implements Serializable{ -wQ^oOJ
J%:/<uCmZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4)+IO;
RandomAccessFile oSavedFile; %Rep6=K*$
long nPos; `u\z!x'
9m!!b{
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public FileAccessI() throws IOException SWjQ.aM
{ Q!Ow{(|
this("",0); 5f'g3'
} |8c:+8
prEu9$:t
8J3@VD.
public FileAccessI(String sName,long nPos) throws IOException O+p-1 C$\
{ tNuCxb-
oSavedFile = new RandomAccessFile(sName,"rw"); j'Y"/<
this.nPos = nPos; 04PoBv~g
oSavedFile.seek(nPos); .k,Jt+
} Lv5X 'yM
aZjef
2\63&C^
public synchronized int write(byte[] b,int nStart,int nLen) 3zTE4pHzu+
{ fj-pNl6Gf
int n = -1; 0\Yx.\X,
try{ ,0uo&/Y4L
oSavedFile.write(b,nStart,nLen); [AX"ne#M*
n = nLen; [TK? P0
} Wx?&igh
catch(IOException e) Cld<D5\|f+
{ 8| e$
e.printStackTrace (); 9;]wF8h
} B >u,)
D<bU~Gd,P
.D,?u"fk|
return n; hK39_A-
} ;eW'}&|LV
r*N~. tFo
i=1 }lkq
} K@jSr*\'
w,![;wG
A?Nn>xF9X
/* WiNr866nB
**SiteInfoBean.java J[!x%8m
*/ i6F:C &.
package NetFox; 1rv$?=Z
,.oa,sku
r'd:SaU+
public class SiteInfoBean { <,@H;|mZ
}*.:Hv"
w`j*W$82
private String sSiteURL; //Site's URL [T4 pgt'H
private String sFilePath; //Saved File's Path lj EB
private String sFileName; //Saved File's Name (3ZvXpzvF
private int nSplitter; //Count of Splited Downloading File =s0g2Zv"\
pfL2v,]g
$!F&>=o
public SiteInfoBean() 7}d$*C
{//nSplitter的缺省值为5 E#<7\p>
//default value of nSplitter is 5 EvqUNnjR
this("","","",5); i'!jx.
} cBab2/
8lOZIbwS
BZJKiiD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C!7U<rI
{ @1<omsl
sSiteURL= sURL; #.)xm(Ys
sFilePath = sPath; ]{|fYt_-
sFileName = sName; "u<jbD
this.nSplitter = nSpiltter; /[Bl
}%!FMXe
Lf^5Eo/ 5A
} JlC<MQ?
J[}gku?C;
&;ZC<?wS
public String getSSiteURL() ~VqFZasV
{ yX7CN5vVl
return sSiteURL; }c` ?0FQ
} (B>)2:T1
_8[UtZYG
^e?$ ]JiA!
public void setSSiteURL(String value) F2bm+0vOJ
{ 3VcT7y*{P
sSiteURL = value; $R%+*
} U_x0KIm
J16=!q()
/&D'V_Q`*
public String getSFilePath() v#<\:|XAg
{ 2q"_^deI5*
return sFilePath; =MTj4VXh"
} 0\5M^:8i3
g|ql 5jW
FNz84qVIx'
public void setSFilePath(String value) >.J'L5 x$
{ W[R]^2QAG
sFilePath = value; s.^c..e75C
} *nYB o\@g
M4TrnZ1D}
qs!>tw
public String getSFileName() <K.Bq]
{ I:F'S#
return sFileName; EvwbhvA(
} 0=OD?48<
E x_L!9>!
D^,\cZbY
public void setSFileName(String value) B;eW/#`
{ WYSck&9
sFileName = value; T?H\&2CLT
} ZJ^s}
0SJ{@*
7'_nc!ME
public int getNSplitter() Sdgb#?MR|
{ %S{o5txo
return nSplitter; nHSTeFI?
} qPsyqn?Y|
d4d\0[
&bB6}H(
public void setNSplitter(int nCount) U+4HG
{ 7}<Sg
nSplitter = nCount; 'oC$6l'rQ
} 8]My k>
} 54=}GnZN
jo_o`j
mYX56,b}5
/* ewo*7j4*
**Utility.java XDHLEG-u(
*/ xttYn]T
package NetFox; m+Y@UgB
U8YO0}_z
NtHbwU,
public class Utility { kfVZ=`p}
0;vtdM[_
)nhfkW=e
public Utility() 6yN" l Q7
{ %h0D)6j
)j\r,9<K+5
mDZ=Due1
} (Ar?QwP9>
w]n4KR4
//线程睡眠 .SG0}8gW
public static void sleep(int nSecond) #xlZU
{ /[0F6
try{ gC0;2
Thread.sleep(nSecond); =Wj{]&`
} =h(7rU"Yz
catch(Exception e) iNt 4>
{ otU@X 3<_
e.printStackTrace (); _]P a>8X*
} _=uviMuE
} %=BtOM_2
. /Y&\<
//日志 m+H%g"Zj
public static void log(String sMsg) # 2d,U\_
{ hPcS, p{%
System.err.println(sMsg); 1c'79YU
} 5KK{%6#f\
"rVU4F)
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public static void log(int sMsg) THJ 3-Ug
{ Axf^hBP
System.err.println(sMsg); l7ZB3'
} (JWv *p
} `\wUkmH
Bn{)|&;
$iwIF7,\P
/* ^dh=M5xz)
**TestMethod.java ?<E0zM+
*/ :aH%bk
package NetFox; MZ)T0|S_
uw_H:-J
=w6}\ 'X
public class TestMethod { L/)B}8m\
*y{+W
V+46R ]
public TestMethod() )PwQ^||{
{ ///xx/weblogic60b2_win.exe +uELTHH=
try{ /0 _zXQyV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x=h0Fq,T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4HW;
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0:. 6rp
fileFetch.start(); ":V%(c
} B.}cB'|
catch(Exception e){e.printStackTrace ();} V(r`.75
V7BsEw
B7|c`7x(
} -rO*7HO
5:$Xtq
n6/fan;
public static void main(String[] args) Mo_$b8i
{ bTiBmS
new TestMethod(); >d97l&W
} J)#S-ZB+'k
} ac|/Y$\w
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