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)); }f*S 9V
} XmR5dLc8
for(int i=0;i<nEndPos.length-1;i++) <Wq{ V;$
{ /hR]aw
nEndPos = nStartPos[i+1]; Jtk(yp{Zz
} [p<[83' ]
nEndPos[nEndPos.length-1] = nFileLength; ~]+ jn
} e:occT
} |:BYOxAYZ8
j"8N)la
izo $0
//启动子线程 jo#F&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9F!&y-
for(int i=0;i<nStartPos.length;i++) ~[6|VpGc:
{ !qv;F?2 <g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k]YGD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W}3vY]
nStartPos,nEndPos,i); feHAZ.8rp+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *&MkkI#
fileSplitterFetch.start(); LRs;>O
} d69VgLg
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L@GD$F=<0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^2@~AD`&h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (Ad!hyE(
nEndPos = " + nFileLength); o|C{ s
// fileSplitterFetch[nPos.length-1].start(); ;wB3H
T0jJp7O
~cwwB{
//等待子线程结束 pdqh'+5
//int count = 0; mr.DP~O:9p
//是否结束while循环 _"`h~jB
boolean breakWhile = false; f d5~'2
X|G+N(`|(
_gh7_P^H=d
while(!bStop) 3/05ee;|
{ Bk<P~-I
write_nPos(); *h9vMks o
Utility.sleep(500); P^-9?uBno
breakWhile = true; #IDCCD^1=
^123.Ru|t
$vz%
for(int i=0;i<nStartPos.length;i++) ^Yz05\
{ ZZ7U^#RT
if(!fileSplitterFetch.bDownOver) d5hE!=
{ =<xbE;,0
breakWhile = false; k=_@1b-
break; W -&5 v
} _Oq\YQb v
} ~V)E:(
if(breakWhile) ;_\P;s
break; p60D{UzU
Eq{TZV
#CmBgxg+M
//count++; pT tX[CE
//if(count>4) XvY-C
// siteStop(); c-d}E!C:
} w.H+$=aK
?C3cPt"
lX3h'h
System.err.println("文件下载结束！"); 3R {y68-S
} ~O-8h0d3
catch(Exception e){e.printStackTrace ();} =oJiNM5_u
} X3yr6J[ ^
oJ:J'$W(
= ;d<Ikj
//获得文件长度 L4b4X
public long getFileSize() g!ww;_
{ cK&oC$[r-
int nFileLength = -1; ibyA~YUN/
try{ %\0 Y1!Hw
URL url = new URL(siteInfoBean.getSSiteURL()); KHtY +93
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AAcbY;
httpConnection.setRequestProperty("User-Agent","NetFox"); |#6Lcz7[
Ip0q&i<6
.<dmdqk]
int responseCode=httpConnection.getResponseCode(); 4^&vRD,
if(responseCode>=400) ev $eM
{ 5>Q)8`@E
processErrorCode(responseCode); u7d]%<~'$F
return -2; //-2 represent access is error {,=,0NQKn
} `>Cx!sYhV
>^&+,*tsS4
r8rR_M{P
String sHeader; oV`sCr5%
T!bu}KO
se[};t:
for(int i=1;;i++) m@YLZ
{ r;z A `
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5,C,q%2
//Utility.log(in.readLine()); -wB AFr
sHeader=httpConnection.getHeaderFieldKey(i); o*_D
if(sHeader!=null) 5mU_S\)4:z
{ ^>fs
if(sHeader.equals("Content-Length")) "L]_NST
{ `Z-`-IL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c+=&5=i[3
break; SCij5il%
} 8*wI^*Q
} e+wd>iiB
else zu#o<6E{
break; / <p HDY
} 0N.*c
} _q 8m$4
catch(IOException e){e.printStackTrace ();} @^Oww(I
catch(Exception e){e.printStackTrace ();} -bwl~3ZTi
'#PT C,0UJ
uZ+<
Utility.log(nFileLength); a0R]hENC
1*fA>v
_Gu ;U@
return nFileLength; |Bp?"8%*l
} /!hW6u5
T (qu~}
cO:x{~
//保存下载信息（文件指针位置） {\B!Rjt[T
private void write_nPos() J5k%
{ iwbjjQPr
try{ /03>|Juo
output = new DataOutputStream(new FileOutputStream(tmpFile)); r`2& o
output.writeInt(nStartPos.length); \ (,2^T'$J
for(int i=0;i<nStartPos.length;i++) F}Au'D&n_
{ @lwqkJ
// output.writeLong(nPos); |($pXVLH`
output.writeLong(fileSplitterFetch.nStartPos); tz,FK;8
output.writeLong(fileSplitterFetch.nEndPos); uT1x\Rt|e
} _D~a4tgS
output.close(); YdFCYSiS
} z2V!u\It
catch(IOException e){e.printStackTrace ();} )7^jq|
catch(Exception e){e.printStackTrace ();} &kG<LGXP#
} -Q; w4@
utr_fFu
U^xFqJY6
//读取保存的下载信息（文件指针位置） XL:7$
private void read_nPos() ]9' \<uR
{ rhrlEf@
try{ ]Uu/1TTf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +~-|( y
int nCount = input.readInt(); DcOLK\
nStartPos = new long[nCount]; J?&9ofj&
nEndPos = new long[nCount]; r$KDNa$/a
for(int i=0;i<nStartPos.length;i++) xInWcQ
{ mWh:,[o
nStartPos = input.readLong(); L-XTIL$$
nEndPos = input.readLong(); S'txY\
} R`c5-0A
input.close(); 4T:ZEvdzf
} 4Xz|HU?
catch(IOException e){e.printStackTrace ();} <*[(t;i
catch(Exception e){e.printStackTrace ();} %X3T<3<
} ps2C8;zT
_xJ&p$&
`)'YU^s
private void processErrorCode(int nErrorCode) L,i-T:Z~=
{ }sFHb[I &
System.err.println("Error Code : " + nErrorCode); IoC,\$s,
} [K5afnq`
B-RaAiE@
>(3y(1;
//停止文件下载 ;/v^@
public void siteStop() .FeEK(
{ u%FA.
bStop = true; PYZ8@G
for(int i=0;i<nStartPos.length;i++) {0?76|
fileSplitterFetch.splitterStop(); %:NI@59
!59q@Mya[
ZR1EtvVG
} '>Z Ou3>
} Q]8r72uSk
//负责部分文件的抓取 OA_ %%A;o
**FileSplitterFetch.java fIu/*PFPVY
*/ u7S7lR"lxW
package NetFox; (j(6%U
2n\EZ
n'SnqJ&}
import java.io.*; $3So`8Bm[$
import java.net.*; ^Kn}{m/3Y
hQ9VcS6=gD
+:b|I'S
public class FileSplitterFetch extends Thread { r_QWt1K
~sOAm
q N>j2~
String sURL; //File URL *p"%cas
long nStartPos; //File Snippet Start Position hT<v8
long nEndPos; //File Snippet End Position j*GYYEY
int nThreadID; //Thread's ID Qk((H~I}
boolean bDownOver = false; //Downing is over d;`JDT
boolean bStop = false; //Stop identical dI`b AP;\
FileAccessI fileAccessI = null; //File Access interface s\@!J.Da
hUqIjcuL4
).\%a h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~MOIrF
{ 9BP-Iet
this.sURL = sURL; -{HA+YL H
this.nStartPos = nStart; [l0>pHl@
this.nEndPos = nEnd; OmsNo0OA
nThreadID = id; FbF P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (f7R~le
} qTG/7tn "
\j4TDCs_[
sq_ f[!
public void run() OF}vY0oiw?
{ zMtx>VI
while(nStartPos < nEndPos && !bStop) LKhUqW
{ q%nWBmPZ~y
BRzrtK
7"1M3P5*8
try{ gkDB8,C<j
URL url = new URL(sURL); XOU 9r(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4h-tR
httpConnection.setRequestProperty("User-Agent","NetFox"); {D$+~lO
String sProperty = "bytes="+nStartPos+"-"; +5voAx!
httpConnection.setRequestProperty("RANGE",sProperty); hDCR>G
Utility.log(sProperty); L+&$/1h]
zpJQ7hym
Zv-#v
InputStream input = httpConnection.getInputStream(); vLq_l4l
//logResponseHead(httpConnection); (<|,LagTuc
3:s!0ty"
*~cq (PFQ
byte[] b = new byte[1024]; O.i.<VD7
int nRead; r+>gIX+Fl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0`:0m/fsU
{ ^I7iEv
nStartPos += fileAccessI.write(b,0,nRead); arm26YA-,
//if(nThreadID == 1) 29:] cL(5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o!:
} l4RZ!K*X_"
cJMp`DQzc
Nzf tc
Utility.log("Thread " + nThreadID + " is over!"); Lc=t,=OhGe
bDownOver = true; m;'ebkq
//nPos = fileAccessI.write (b,0,nRead); w=,bF$:fIW
} 13kl\<6
catch(Exception e){e.printStackTrace ();} b-,4< H8m
} f<<1.4)oSV
} (cx Q<5
tw,uV)xm
FG/1!8F
//打印回应的头信息 Ko:<@h
public void logResponseHead(HttpURLConnection con) !Wgi[VB
{ !ap}+_IA7^
for(int i=1;;i++) Ejmpg_kux
{ Pd)mLs Jg
String header=con.getHeaderFieldKey(i); 3VaL%+T$,
if(header!=null) 3%P<F>6 J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Cs))9'cD]
Utility.log(header+" : "+con.getHeaderField(header)); c~SR@ZU
else KSz;D+L\
break; s^#B*
} #ozui-u>
} n&1q*
wNtC5
:<hM@>eFn
public void splitterStop() #A\@)wJ
{ k..AP<hH
bStop = true; }20~5!
} uVN2}3!)Y
kntYj}F(
W[/Txc0$
} WUrE1%u
t^ Ge"
E6XDn`:
/* \xG_q>1_
**FileAccess.java LGB}:;$AL
*//文件访问(定位，写) 6+!$x?5|NP
package NetFox; -!q^/ux
import java.io.*; - ({h @
q#=HBSyM
5/8=Do](
public class FileAccessI implements Serializable{ 2)hfYLi
xIA]5@;a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }k;wSp[3
RandomAccessFile oSavedFile; 7cB/G:{
long nPos; :er(YWF:
F%P"T%|
$7" Y/9Y
public FileAccessI() throws IOException 0nbY~j$A=
{ (@m/j2z
this("",0); H-\Ym}BGu
} !#d5hjoX
&+ "<ia(
`R;i1/
public FileAccessI(String sName,long nPos) throws IOException LI*=T
{ \#4mPk_"
oSavedFile = new RandomAccessFile(sName,"rw"); fqjBor}
this.nPos = nPos; DSQ2|{
oSavedFile.seek(nPos); 9TX2h0U?
} LAkBf
PriLV4?
kMJ}sS
public synchronized int write(byte[] b,int nStart,int nLen) \HXq~Y
{ zZ6m`]{B9?
int n = -1; 4_kY^"*#"
try{ }ZK%@b>
oSavedFile.write(b,nStart,nLen); ,~q:rh+
n = nLen; eR%\_;}7;
} Qk? WX (`B
catch(IOException e) 4C/G &w&
{ da<>a
e.printStackTrace (); (n`] sbx
} )(0if0D4
`Fie'[F5,)
`JO>g=,4
return n; DQ(0:r
} 7Xx3s@
n]df)a
"iTjiH)Q(
} |.VSw
^s6}[LDW>@
}4N'as/ZO
/* 8OKG@hc
**SiteInfoBean.java qg{gCG
*/ 7HkFDI()1
package NetFox; }f;WYz5
/{f"0]-RA
Qo)Da}uo20
public class SiteInfoBean { &Ts!#OcB,
!m^;wkrY
GF6o
private String sSiteURL; //Site's URL ,A'| Z
private String sFilePath; //Saved File's Path "I66@d?
private String sFileName; //Saved File's Name ~P#mvQE)
private int nSplitter; //Count of Splited Downloading File 0N^+d,Xt.
ltfKqY-
<3!Al,!ej@
public SiteInfoBean() )by7[I0v
{//nSplitter的缺省值为5 Tf~eH!~0
//default value of nSplitter is 5 7mq&]4-G
this("","","",5); m^!:n$
} 4j~q,#$LW
~n-Px)
XVkw/l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +}O -WX?
{ #B<EMGH
sSiteURL= sURL; }[Z'Sg]s
sFilePath = sPath; 2HtsSS#0Q
sFileName = sName; T:u>7?8o
this.nSplitter = nSpiltter; s]%Cz\
f[1cN`|z
E/g"}yR
} s>m2qSu
`Jk0jj6Z
0u1ZU4+EC
public String getSSiteURL() QuqznYSY{
{ }%p:Xv@X!
return sSiteURL; I%u 2 ce
} '{cSWa| #
Rjq Xz6
ss[`*89
public void setSSiteURL(String value) wn.~Dx
{ n74\{`8]o
sSiteURL = value; y92R}e\M
} +9w[/n^,G
.ojEKu+EJ'
gYhY1Mym
public String getSFilePath() 9T;4aP>6j#
{ lhKn&U
return sFilePath; /kY9z~l
} db~^Gqv6k
h{gFqkDoTI
EW|$qLg
public void setSFilePath(String value) }9+;-*m/
{ uR ?W|a
sFilePath = value; N$6e KJ]
} Yy88 5
Q]YB.n3
.JPN';
public String getSFileName() IplOXD
{ *Jgi=,!m
return sFileName; >x{("``D0y
} )GkJ%o#H2
T9 /;$6s*
mY.v:
public void setSFileName(String value) q7X#LYk
{ @khFk.LBD
sFileName = value; {1)A"lQu
} w}gmVJ#p
`Gqe]ZE#"
<Z]#vrq
public int getNSplitter() -B;#pTG
{ SLKplLO
return nSplitter; Wd:pqhLh
} umIGI
bZ\R0[0
s0/O/G?
public void setNSplitter(int nCount) $D1ha CL
{ itg_+%^R
nSplitter = nCount; j(=w4Sd_W
} hm,{C
} I/`"lAFe
8@t8P5(vL
UGSZg|&6#*
/* {V6&((E8
**Utility.java #7i*Diqf9
*/ )i~AXBt}
package NetFox; iApq!u,
&Q3Fgj
,AP0*Ln
public class Utility { eX+36VG\
w*-42r3,'
; ~pgF_
public Utility() r[S(VPo[()
{ G:<f(Gy
cLV*5?gVO
<E2 IU~e
} e$Ksn_wEq
yp#!$+a}
//线程睡眠 AJ\&>6GZ(b
public static void sleep(int nSecond) zmo2uUEd
{ i"h\*B=
try{ w:t~M[kTW
Thread.sleep(nSecond); $*ff]>#
} DZSS
catch(Exception e) :C:6bDQ
{ %L=e%E=m
e.printStackTrace (); *'>_XX
} xDo0bR(
} ev4[4T-(@
GC')50T J
//日志 2? qC8eC
public static void log(String sMsg) $aV62uNf
{ -G(me"Cu
System.err.println(sMsg); wZ(1\ M(
} fz(YP=@ZnP
#EH=tJgO|J
BU:;;iV8
public static void log(int sMsg) =W~7fs
{ ON,[!pc
System.err.println(sMsg); i#'K7XM2
} MgeC-XQM
} |Xt.[1
Tn&_ >R
#`VAw ) eV
/* ;z'&$#pA
**TestMethod.java 8ymdg\I+L
*/ BJjic%V
package NetFox; ,"EaZ/Bl/
2lTt
}J#HIE\RG
public class TestMethod { ]l,D,d81
"^#O7.oVi+
"`qk}n-
public TestMethod() l77 -I:
{ ///xx/weblogic60b2_win.exe =A'>1N
try{ b j&!$')
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g88k@<Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \n{#r`T
SiteFileFetch fileFetch = new SiteFileFetch(bean); i!a!qE.1
fileFetch.start(); ;/Hr ZhOE
} "*bLFORkq'
catch(Exception e){e.printStackTrace ();} K(+=V)'Dz
cXq9k!I%
L^JU{\C
} QLJ\>
`=(<!nXJx
C m:AU;
public static void main(String[] args) bBi>BP=
{ %p 6Ms
new TestMethod(); s~Eo]e
} A%^?z.
} ctP+ECH
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