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)); R8Vf6]s_
} Q'jw=w!|g
for(int i=0;i<nEndPos.length-1;i++) ikV;]ox
{ mL48L57Z
nEndPos = nStartPos[i+1]; 3EICdC
} ^.!jD+=I
nEndPos[nEndPos.length-1] = nFileLength; hyf ;f7`o
} 71{jedT
} A+0-pF2D
}QE*-GVv]
u/u(Z&
//启动子线程 c Pf_B=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U*$xR<8v
for(int i=0;i<nStartPos.length;i++) @i;)`k5b
{ ?e<2'\5v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }ARA K^%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K8_v5
nStartPos,nEndPos,i); HT.*r6Y>g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yQN{)rv
fileSplitterFetch.start(); 7}UG&t{
} 6_bL<:xtY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =zcvR {Dkp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CC`_e^~y=F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \toU zTT
nEndPos = " + nFileLength); $3g{9)}
// fileSplitterFetch[nPos.length-1].start(); lbBWOx/|
i#`q<+/q
\H@1VgmR;
//等待子线程结束 c_D(%Vf5
//int count = 0; _b~{/[s
//是否结束while循环 aLGq<6Ja
boolean breakWhile = false; hDW!pnj1
|j`73@6
c Rq2 re
while(!bStop) VIP7j(#t_g
{ =\WF +r]V
write_nPos(); 1^}I?PbqV
Utility.sleep(500); ^U*y*l$
breakWhile = true; *(?Wzanh
Szgo@x$^
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for(int i=0;i<nStartPos.length;i++) Lz'VQO1U=
{ *7jz(iX
if(!fileSplitterFetch.bDownOver) QS&B"7;g
{ rTIu'
breakWhile = false; 6(f'P_*
break; VWvSt C
} LZRg%3.E
} xf]K
if(breakWhile) ]$@D=g,r
break; ;mG*Rad
`.W2t5Y
`x`[hJ?i
//count++; +O.-o/
//if(count>4) (?na|yd
// siteStop(); 9qB0F_xl
} S'jg#*$
tNi>TkC}`
\g39>;iR
System.err.println("文件下载结束！"); FQDf?d5
} ecghY=%
catch(Exception e){e.printStackTrace ();} Hsf::K x
} _5jT}I<k
N>!:bF
H4w\e#|
//获得文件长度 k2U*dn"9U
public long getFileSize() ?BnU0R_r]
{ (j&:
int nFileLength = -1; \!-BR0+y;
try{ "+F'WCJ-(*
URL url = new URL(siteInfoBean.getSSiteURL()); (jM0YtrD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $oK&k}Q
httpConnection.setRequestProperty("User-Agent","NetFox"); CJ :V%|
!qt2,V
Pb#M7=J/
int responseCode=httpConnection.getResponseCode(); g"!(@]L!@
if(responseCode>=400) "?I#!t%'
{ /o;M ?Nt6
processErrorCode(responseCode); <-umeY"n>
return -2; //-2 represent access is error Wh)D_
} d#g))f;
w7V\_^&Id
7Q}pKq]P
String sHeader; sS>b}u+v#!
%c }V/v_h
pjWRd_h.
for(int i=1;;i++) Yq+1kA
{ kJWg},-\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7>JTQ CJ
//Utility.log(in.readLine()); d~LoHp
sHeader=httpConnection.getHeaderFieldKey(i); ')y2W1
if(sHeader!=null) ]:|B).
{ .,bpFcQ
if(sHeader.equals("Content-Length")) ;A*SuFbV
{ &|/_"*uM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L8VOiK=,
break; ;o_F<68QP
} !(GyOAb
} P!eo#b^S
else Y}:~6`-jj
break; k{}> *pCU
} gxv^=;2C
} m\L`$=eO8
catch(IOException e){e.printStackTrace ();} JE?rp1.
catch(Exception e){e.printStackTrace ();} 3e_tT8
/Nf{;G!kg
$TI^8 3
Utility.log(nFileLength); i+Z)`
O$,Fga
)U@9dV7u
return nFileLength; 95l)s],
} u\]EG{w(
!_S#8"
~||0lj.D
//保存下载信息（文件指针位置） ~KBa-i%o
private void write_nPos() kA:mB;:
{ v/+ <YU
try{ Re$h6sh
output = new DataOutputStream(new FileOutputStream(tmpFile)); G;Li!H
output.writeInt(nStartPos.length); Nd~B$venh
for(int i=0;i<nStartPos.length;i++) s2;~FK#/
{ uoS:-v}/Y~
// output.writeLong(nPos); G{U#9
output.writeLong(fileSplitterFetch.nStartPos); IiU>VLa
output.writeLong(fileSplitterFetch.nEndPos); XB)D".\
} U\KMeaF5e-
output.close(); M.W X&;>
} T ozx0??)
catch(IOException e){e.printStackTrace ();} (bsx|8[
catch(Exception e){e.printStackTrace ();} U"PcNQy
} (2g a:}K
;8sL
f9.?+.^_
//读取保存的下载信息（文件指针位置） BI1M(d#1L"
private void read_nPos() ,>;21\D
{ aZFpt/.d
try{ IDohv[#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *WwM"NFHDd
int nCount = input.readInt(); W0qR?jc
nStartPos = new long[nCount]; rq+_[!
nEndPos = new long[nCount]; _olQ;{ U:
for(int i=0;i<nStartPos.length;i++) y>I2}P
{ l5[5Y6c>
nStartPos = input.readLong(); 2Ez<Iw
nEndPos = input.readLong(); E9:@H;Gc
} #[+# bw_6
input.close(); LOh2eZ"n
} M<vPE4TIr*
catch(IOException e){e.printStackTrace ();} SyWZOE%p
catch(Exception e){e.printStackTrace ();} :gVUk\)
} Vao:9~
n6/Ous
WyN ;lId
private void processErrorCode(int nErrorCode) 0dchOUj
{ Z(mUU]
System.err.println("Error Code : " + nErrorCode); \TV
} Rs%`6et}\
1[FN: hm
5^B79A"}
//停止文件下载 nV'1 $L#
public void siteStop() V=O52?8
{ zF1!a
bStop = true; Abc{<4 z0?
for(int i=0;i<nStartPos.length;i++) [9m3@Yd'
fileSplitterFetch.splitterStop(); FK%b@/7s~
%w;qu1j
&V].,12x
} Jj4HJ9
} I2Xd"RHN
//负责部分文件的抓取 @\K[WqF$$q
**FileSplitterFetch.java vsY?q8+P
*/ WtT;y|W
package NetFox; ~6G `k^!
&7L7|{18
@X==[gQ
import java.io.*; q+ax]=w
import java.net.*; MpV<E0CmE
/bo}I-<2
Z)?$ZI@
public class FileSplitterFetch extends Thread { <kh.fu@.Q
-F5BJk
honh'j
String sURL; //File URL X1j8tg
long nStartPos; //File Snippet Start Position iT]t`7R
long nEndPos; //File Snippet End Position Rh>B# \
int nThreadID; //Thread's ID $7x2TiAL
boolean bDownOver = false; //Downing is over s8h*nZ)v
boolean bStop = false; //Stop identical +QChD*
FileAccessI fileAccessI = null; //File Access interface #:K=zV\
F/5&:e?( )
:eN&wQ5q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tsXKhS;/w
{ + G@N
this.sURL = sURL; zl0{lV
this.nStartPos = nStart; Ak'=l;
this.nEndPos = nEnd; _imuyt".+
nThreadID = id; c%H' jB[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K~W(ZmB
} EVmBLH-a
6^`iuC5
eqx }]#
public void run() 1IXtu
{ )Z7Vm2a
while(nStartPos < nEndPos && !bStop) X\^V{v^-
{ 2]!@)fio`
xS*UY.>
u]p21)m$x
try{ d:kB Zrq
URL url = new URL(sURL); 6o't3Peh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U4D7@KY +m
httpConnection.setRequestProperty("User-Agent","NetFox"); rH@Rh}#yp
String sProperty = "bytes="+nStartPos+"-"; \8vP"Kr
httpConnection.setRequestProperty("RANGE",sProperty); a4Q@sn;]
Utility.log(sProperty); }(EH5jZ'
!fOPYgAGKn
epy2}TI
InputStream input = httpConnection.getInputStream(); zsL@0]e&
//logResponseHead(httpConnection); D|uvgu2
GppCrQ%Ra|
,\4]uZ<
byte[] b = new byte[1024]; c_8&4
int nRead; <WXVUEea
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x,B] J4
{ 'uL4ezTtA
nStartPos += fileAccessI.write(b,0,nRead); (x=$b(I
//if(nThreadID == 1) 7KC>?F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HuhQ|~C+~
} \YP,}_~
E7Lqa S
gV_v5sk
Utility.log("Thread " + nThreadID + " is over!"); jn(x-fj6R
bDownOver = true; c1YDln
//nPos = fileAccessI.write (b,0,nRead); "@Vyc6L
} *22Vc2[i;
catch(Exception e){e.printStackTrace ();} qO6M5g:
} wgl<JO
} )Sn0Y B
$xO8?
m:@y_:X0
//打印回应的头信息 8Qvs\TY
public void logResponseHead(HttpURLConnection con) `v*HH}aDO
{ Wjb_H (D
for(int i=1;;i++) Be6Yh~m
{ rT2Njy1
String header=con.getHeaderFieldKey(i); xo>0j#
if(header!=null) Ho &Q}<(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,!orD1,'
Utility.log(header+" : "+con.getHeaderField(header)); K%q5:9m
else rc_m{.b
break; M @5&.
} ]!/
} J0xHpe
&@iOB #H
nFnM9 pdMK
public void splitterStop() ;;0'BdsL`
{ |UTajEL
bStop = true; o1AbB?%=
} l=DF)#>w
AtQ.H-8r
$*q|}Tvl#
} :ld~9
{'b;lA]0
5m8u:6kQu
/* )/RG-L
**FileAccess.java 4'QX1p
*//文件访问(定位，写) uw;Sfx,s
package NetFox; VF`!ks
import java.io.*; fyQOF ItM
CsZ~LQ=DB
}c/p;<
public class FileAccessI implements Serializable{ ';C'9k<P:
gk6f_0?X'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1!z{{H;W
RandomAccessFile oSavedFile; 'Lu<2=a~
long nPos; eiMP:
*yBVZD|?H
%8*:VR
public FileAccessI() throws IOException DY2*B"^
{ /VYT](
this("",0); "&6vFmr
} ^/C\:hw
eF+F"|1h
'f( CN3.!
public FileAccessI(String sName,long nPos) throws IOException X1#Ar)
{ s~M$Wo8
oSavedFile = new RandomAccessFile(sName,"rw"); x^ `/&+m
this.nPos = nPos; VYG@_fd!x
oSavedFile.seek(nPos); <6UXk[y
} PUR,r%K`
uu6 JZp
| 0
public synchronized int write(byte[] b,int nStart,int nLen) }UPC~kC+Z
{ BUXE s0]Lv
int n = -1; q T6y&
try{ "OLg2O^
oSavedFile.write(b,nStart,nLen); ?+zFa2J
n = nLen; ^4`aONydl
} 0qS/>u*
catch(IOException e) Wga2).j6
{ x,gk]Cf
e.printStackTrace (); _dKMBcl)E
} qPDNDkjDD
Xb"i/gfxt
eoiz]L
return n; 5,Fq:j)MxW
} Skr(C5T
r#zcl)rbU
wAHuPQ&_Q
} JSL&` `
}#ink4dK:
t3)6R(JC
/* lOm01&^"E
**SiteInfoBean.java H_&to3b(
*/ MG?,,8sO
package NetFox; m)A:w.o
;@Zuet
0YiTv;mq;
public class SiteInfoBean { \Oq2{Sx\
;EBKzB
{o~TbnC
private String sSiteURL; //Site's URL B $u/n
private String sFilePath; //Saved File's Path _=HaE&
private String sFileName; //Saved File's Name |dR}S!fmG
private int nSplitter; //Count of Splited Downloading File 3Q,&D'];[
k8?._1t
z"f@iJX?2
public SiteInfoBean() U'=8:&
{//nSplitter的缺省值为5 h$8h@2%
//default value of nSplitter is 5 6{6hz8
this("","","",5); ;"M6}5dQ4
} d88A.Z3w
toGiG|L
w[X-Q+7p(t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }u;K<<h:
{ x,C8):\t`B
sSiteURL= sURL; LK}g<!o(
sFilePath = sPath; 2E1`r@L
sFileName = sName; f2e;N[D
this.nSplitter = nSpiltter; D$>!vD'
t=B1yvE"
I8XP`Ccq
} ^6 wWv&G[8
sU>IETo
,zgz7
public String getSSiteURL() ,sitOy}ks
{ o< @![P
return sSiteURL; rd7p$e=i
} -Cyo2wk
xt}.0dC!/%
O}i+1
public void setSSiteURL(String value) ,IB\1#
{ LDQ,SS,
sSiteURL = value; u\ _yjv#
} e|oMbTZ5m
{D[6=\F
k9%o{Uzy
public String getSFilePath() >ZJ]yhbhK
{ 8&U Mmbgy
return sFilePath; 0si1:+t-[+
} Mp/l*"(
X,G<D}
NK qIx
public void setSFilePath(String value) 4s7 RB
{ wQG?)aaM
sFilePath = value; ,ayEZ#4.m
} =mXC,<]
$wAR cS
Ba[,9l[
public String getSFileName() W yM1s+@
{ - VJx)g
return sFileName; =803rNe
} vCP[7KhGj
qb[hKp5K6
L2>e@p\>
public void setSFileName(String value) |Y K,&
{ &{e ]S!D
sFileName = value; ulxlh8=
} U;W9`JT<.f
lU doMm
WkXgz6 P
public int getNSplitter() _tHhS@
{ Mz&/.A
return nSplitter; X$5
} ( unmf,y
/<)Vd
KRL.TLgq)
public void setNSplitter(int nCount) X&WP.n)
{ Z5Lmg
nSplitter = nCount; fHd[8{;P:
} :|n[zjK/S
} 9)7$UQY
2VRGTx
`h@fW- r
/* di/QJrw
**Utility.java ;mEn@@{
*/ 2{?]W/&fS
package NetFox; Dizz?O
42]7N3:'
`rVru= zoy
public class Utility { E[t0b5h
s$Vv
N" L&Z4Z
public Utility() 9nN1f@Y
{ 36{GZDGQ
>[Vc$[62
;p+'?%Y}
} To(I<W|{
:\|A.# U
//线程睡眠 V<UChD)N`
public static void sleep(int nSecond) J'Pyn
{ vS\2zwb}
try{ yD~,+}0)
Thread.sleep(nSecond); <-k!
} C7S\4rDJ
catch(Exception e) ,40OCd!
{ ],SQD3~9
e.printStackTrace (); Ysu\CZGX
} '$OUe {j<
} 3A`Gx#
YTyrX
//日志 ^m%#1Zd
public static void log(String sMsg) Uuy$F
{ 0S4BV%7F
System.err.println(sMsg); R1H^CJ=v0
} *#YZm>h
U1r]e%df)
rD=D.1_
public static void log(int sMsg) 5Rl\& G\
{ (|BY<Ac3
System.err.println(sMsg); ULAr!
} qf(mJlU
} KZjh<sjX|
zzZEX
,*iA38d.!
/* -~{Z*1`,
**TestMethod.java nq{/fD(2
*/ 6|NH*#s
package NetFox; n.+'9Fj
es*$/A
\o!3TK"N
public class TestMethod { [@Ac#
.j:,WF<"l5
-!XG>Z
public TestMethod() dQ8RrD=$&
{ ///xx/weblogic60b2_win.exe hty'L61\z
try{ Q!P%duO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &DMC\R*j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 59oTU
SiteFileFetch fileFetch = new SiteFileFetch(bean); NVb}uH*i
fileFetch.start(); A5Hx$.Z
} kK=VG< :M
catch(Exception e){e.printStackTrace ();} $YX{gk>
;NA5G:eQ
VwI
} Gk~aTO
K(?V]Mxl6
9;L4\
public static void main(String[] args) WPRk>j
{ @SD XJJh
new TestMethod(); "0!h-bQN
} 9:{<:1?
} 5$=[x!x
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