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)); #!KE\OI;@5
} YgV817OV
for(int i=0;i<nEndPos.length-1;i++) 1.9}_4!
{ 4l45N6"
nEndPos = nStartPos[i+1]; [ $n_6
} <r`2)[7N
nEndPos[nEndPos.length-1] = nFileLength; qXe8Kto
} !pdb'*,n
} KOuCHqCfq
5m(^W[u `
Q &K
//启动子线程 JU5C}%Q6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b4ONh%
for(int i=0;i<nStartPos.length;i++) hP)LY=-2
{ u'W8;G*~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iBgx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "z=SO1
nStartPos,nEndPos,i); [>%xd)8.c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1gy.8i
fileSplitterFetch.start(); &&:YVd
} !~D}/Q;#}\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,+{LYF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pjjewy1}^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", doy`C)xI
nEndPos = " + nFileLength); DOJN2{IP
// fileSplitterFetch[nPos.length-1].start(); }$Tl ?BRpU
W_8wed:b
B%76rEpvW;
//等待子线程结束 D(RTVef
//int count = 0; ^y1j.M@q
//是否结束while循环 (/j/>9iro
boolean breakWhile = false; T iiWp!mX
H>B&|BO_[
j; y#[|
while(!bStop) !F1N~6f
{ UsQ+`\|
write_nPos(); ;J2zp*|
Utility.sleep(500); q$tUH)0
breakWhile = true; 9"A`sGZ
?Yk.$90
=4PV;>X
for(int i=0;i<nStartPos.length;i++) ~W+kiTsD?
{ j=aI9p
if(!fileSplitterFetch.bDownOver) DLMM/WJg@
{ &*G#H~\
breakWhile = false; >kp?vK;'B
break; IrhA+)pdse
} QPg8;O
} iQ fJ
if(breakWhile) C3],n
break; i/ )am9
Tewb?:
]d0tE?9
//count++; Sf7\;^
//if(count>4) *b/`Ya4
// siteStop(); E5xzy/ZQ
} ZR]25Yy
)~] (&
ve/<=IR Zo
System.err.println("文件下载结束！"); _5# y06Q
} k+Czj
catch(Exception e){e.printStackTrace ();} 8b-Q F
} 2Mmz%S'd
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s,=i_gyPQ
//获得文件长度 orfO^;qTY
public long getFileSize() !0@Yplj
{ U4-g^S[
int nFileLength = -1; Z99>5\k
try{ D.Q=]jOs
URL url = new URL(siteInfoBean.getSSiteURL()); ()+<)hg}2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^,8)iV0j_
httpConnection.setRequestProperty("User-Agent","NetFox"); 3?7\T#=
L=8<B=QT$
}\#Rot>Y
int responseCode=httpConnection.getResponseCode(); TDNQu_E
if(responseCode>=400) HO%wHiv1X
{ \cUNsB5
processErrorCode(responseCode); PCM-i{6/
return -2; //-2 represent access is error RyK\uv
} R0vIbFwj
5Z\#0":e
ws|;`
String sHeader; .#Z%1U%P.
#9xd[A: N
Rh{zH~oZ
for(int i=1;;i++) 7-T{a<g
{ Vle@4]M\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sq[iY
//Utility.log(in.readLine()); d%,eZXg'
sHeader=httpConnection.getHeaderFieldKey(i); WKIoS"?-F
if(sHeader!=null) 7cO n9fIE
{ U($dx.`v#
if(sHeader.equals("Content-Length")) H_ox_ u}
{ Nkl_Ho,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s,n0jix@
break; ^!z[t\$
} ez^@NK
} ;z:UN}
else ^8Q62
break; G *;a^]-
} SNE#0L'}
} V8-oYwOR
catch(IOException e){e.printStackTrace ();} q+]h=:5=I
catch(Exception e){e.printStackTrace ();} ^(h+URFpA
TGe;HZ
T{Uc:Z
Utility.log(nFileLength); *"n vX2iz
okv1K
C #6dC0
return nFileLength; dJ""XaHqf
} [P7N{l=I
&2zq%((r
0B@Jity#!
//保存下载信息（文件指针位置） Qj6/[mUr~
private void write_nPos() p2udm!)J
{ y+6o{`0
try{ <5jzl
output = new DataOutputStream(new FileOutputStream(tmpFile)); y2vUthRwo
output.writeInt(nStartPos.length); dW~*e2nq
for(int i=0;i<nStartPos.length;i++) i35=Y~P-
{ o1Q7Th
// output.writeLong(nPos); fasgmi}
output.writeLong(fileSplitterFetch.nStartPos); FE!lok
output.writeLong(fileSplitterFetch.nEndPos); sHl>$Qevz
} `zXO_@C
output.close(); #ap9Yoyk\
} q]N:Tpm9
catch(IOException e){e.printStackTrace ();} D{4YxR PX
catch(Exception e){e.printStackTrace ();} [$"n^5_~
} lBFMwJU)
q^L<X)
p4i]7o@
//读取保存的下载信息（文件指针位置） 16i"Yg!*
private void read_nPos() x61U[/r
{ H;fxxu`cS
try{ hq/k*;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MxcFvo*LCp
int nCount = input.readInt(); 5N*Ux4M
nStartPos = new long[nCount]; 7=OQ8IM!
nEndPos = new long[nCount]; Nn"+w|v[ev
for(int i=0;i<nStartPos.length;i++) u(t#Ze~Y1
{ *b}lF4O?
nStartPos = input.readLong(); L^4-5`gj
nEndPos = input.readLong(); | j a-
} i?:_:"^x
input.close(); [[Y0
} z,bQQ;z9
catch(IOException e){e.printStackTrace ();} QtqfG{
catch(Exception e){e.printStackTrace ();} 0,rTdjH7
} 'X!?vK^]p
Bv.`R0e&
fpN- o
private void processErrorCode(int nErrorCode) Ttc[Q]Ri
{ +_xOLiu
System.err.println("Error Code : " + nErrorCode); A7`1-#
} F]t(%{#W
pzgSg[|
{TRsd
//停止文件下载 e$uiJNS2
public void siteStop() XNb ZNaAd
{ F.=Bnw/-
bStop = true; GSQ/NYK
for(int i=0;i<nStartPos.length;i++) u% n*gcY
fileSplitterFetch.splitterStop(); b-*3 2Y%
V{&rQ@{W
`TPOCxM Mo
} m7GR[MR
} u=/CRjot
//负责部分文件的抓取 U*P. :BvG
**FileSplitterFetch.java *(>}Y
*/ &gE 75B
package NetFox; mA@Me7m}
"a/ Q%.P
u@%r
import java.io.*; ~ Yngkt
import java.net.*; I1>N4R-j
.eO?Z^
h"[+)q%L
public class FileSplitterFetch extends Thread { dN}#2Bo=
t/PlcV_M"
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String sURL; //File URL |xvy')(b
long nStartPos; //File Snippet Start Position 0% #<c p
long nEndPos; //File Snippet End Position V$rlA'+1v
int nThreadID; //Thread's ID JQ-gn^tsy
boolean bDownOver = false; //Downing is over 1G'`2ATF*
boolean bStop = false; //Stop identical d4 (/m_HMu
FileAccessI fileAccessI = null; //File Access interface ~E^,=4
"AhTH.ZP
G>+1*\c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O8W7<Wc|z
{ 7 +@qB]Bi<
this.sURL = sURL; =}:)y0L
this.nStartPos = nStart; K[7EOXLy
this.nEndPos = nEnd; e<#DdpX!H~
nThreadID = id; I;?X f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wB{;bB{
} /Y2/!mU</
*I0-O*Xr
rUjdq/I:Z
public void run() oejfU;+$
{ }O4se"xK
while(nStartPos < nEndPos && !bStop) Ep4Hqx $
{ FHPXu59u
!HJ$UG/\
)I-fU4?
try{ [J0v&{)?
URL url = new URL(sURL); N8`4veVBx'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DF{Qw@P!
httpConnection.setRequestProperty("User-Agent","NetFox"); 6Ik,zQL
String sProperty = "bytes="+nStartPos+"-"; leiW4Fj
httpConnection.setRequestProperty("RANGE",sProperty); N9rBW
Utility.log(sProperty); O!Z|r?
@v*/R%rv t
5Fm=/o1
InputStream input = httpConnection.getInputStream(); |uH%6&\
//logResponseHead(httpConnection); Px>va01n
Q9`QL3LQD
a%Jx `hx
byte[] b = new byte[1024]; 5Y3i|cj
int nRead; LN_OD5gZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tB'V
{ f0LP?]
nStartPos += fileAccessI.write(b,0,nRead); y9|K|xO[
//if(nThreadID == 1) <d7V<&@o=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7.+#zyF
} [;b=A
^-M^gYBR
S?0)1O
Utility.log("Thread " + nThreadID + " is over!"); :b,^J&~/)1
bDownOver = true; N|2y"5
//nPos = fileAccessI.write (b,0,nRead); Y3ZK%OyPR
} J%]D%2vnk`
catch(Exception e){e.printStackTrace ();} ^5t
} Ut)r&?
} 2_t=P|Uo
9(!]NNf!
cDXsi#Raj
//打印回应的头信息 O8N[Jl
public void logResponseHead(HttpURLConnection con) ~H}en6Rc
{ VZIR4J[\.
for(int i=1;;i++) www`=)A;
{ )OsLrq/
String header=con.getHeaderFieldKey(i); s/1 #DM"
if(header!=null) KIVH!2q;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8S;CFyT\n
Utility.log(header+" : "+con.getHeaderField(header)); ]^\8U2q}
else br,+45:
break; xqHL+W
} ; W7Y2Md
} s-VSH
fH8!YQG8$
&VWlt2-R0h
public void splitterStop() Cv=GZGn-
{ b]]N{: I
bStop = true; ^Dx#7bsDZR
} ]wuy_+$
xkA2g[
.]}N55M
} DjW$?>
W%!@QY;E(
y02u?wJ
/* XvSIWs
**FileAccess.java }+Vv0jX|V
*//文件访问(定位，写) IdM*5Y>f
package NetFox; YJ2ro-X
import java.io.*; []&(D_e"
9F+P@Kp
oaDsk<(j;R
public class FileAccessI implements Serializable{ 1ZKzumF
H"+c)FGi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R.1Xst &i
RandomAccessFile oSavedFile; M}.b" ljZ
long nPos; =J|sbY"]
<5Mrp"C[i
}G1&]Wt_
public FileAccessI() throws IOException ;~sr$6
{ 04y!\
this("",0); CM~MoV[k7e
} =V^@%YIn
i|\{\d
a]VGUW-
public FileAccessI(String sName,long nPos) throws IOException $<ddy/4
{ GF--riyfB
oSavedFile = new RandomAccessFile(sName,"rw"); iY.eJlfH
this.nPos = nPos; \}inT_{g
oSavedFile.seek(nPos); Y~"9L|`f/
} wTpD1"_R
r7)@M%A
@%@zH%b
public synchronized int write(byte[] b,int nStart,int nLen) FUaNiAr[
{ _JOP[KHb
int n = -1; )45_]tk>
try{ 4-:7.I(hq
oSavedFile.write(b,nStart,nLen); =p\Xy*
n = nLen; ,sb1"^Wc
} ~|) 9RUXr>
catch(IOException e) 4S *,\q]q
{ T#iU+)-\%
e.printStackTrace (); GFR!n1Hv
} u;n(+8sz
"oE*9J?e
K~>jApZ%
return n; ~5t?C<wo
} xtJAMo>g
7>x;B
A'DVJ9%xB
} u3wL<$2[8
@ u1Q-:
J#7(]!;F
/* -fux2?8M
**SiteInfoBean.java Z! YpklZ?~
*/ dp^N_9$cdO
package NetFox; v"k4ATWP
AA7#c7
aii'}c
public class SiteInfoBean { I>((o`
O:u%7V/
2xmT#m
private String sSiteURL; //Site's URL <PD|_nZT
private String sFilePath; //Saved File's Path [~?M/QI9
private String sFileName; //Saved File's Name 0QR.
private int nSplitter; //Count of Splited Downloading File ,35Ag#va
zPQ$\$7xB
om7`w ]
public SiteInfoBean() 4!2SS
{//nSplitter的缺省值为5 d8.ajeN]o
//default value of nSplitter is 5 +{xG<Wkltz
this("","","",5); FT_k^CC
} b]dxlj} <
s, -*q}
|+/$ g.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )_O.{$ to
{ Y\u_+CG*
sSiteURL= sURL; ' PL_~
sFilePath = sPath; s?<!&Y
sFileName = sName; +UaO<L
this.nSplitter = nSpiltter; dP3VJ3+ %
t~~r-V":
kGj]i@(PA4
} o*)@oU
drX4$Kdf]
&z0iLa4q)
public String getSSiteURL() r!M#7FDs(
{ vz,LF=s2
return sSiteURL; P6E1^$e
} /'NUZ9
sbjtL,
`]LODgk~
public void setSSiteURL(String value) h*waRD
{ a^*B5G1(&
sSiteURL = value; `7>K1slQ}S
} ws().IZ
eU"mG3__
G,/Gq+WX
public String getSFilePath() eu=|t&FKk
{ q"p#H8
return sFilePath; !pV<n
} 1G_xP^H!
>";%2u1
Ebbe=4
public void setSFilePath(String value) _"v~"k 90^
{ :28@J?jjO
sFilePath = value; T/5nu?v
} *<CxFy;|
Obg@YIwn
}*ODM6
public String getSFileName() Z c<]^QR
{ z}mvX.j7
return sFileName; ?PYNE
} Cd9t{pQD4
u-1@~Z
,iohfZz
public void setSFileName(String value) >T(M0Tkt
{ 5GUH;o1m
sFileName = value; wz)m{:b<
} =yo=q)W
4&H+hN{3
kEx8+2s=M
public int getNSplitter() 0vcET(
{ #VQ36pCd
return nSplitter; taBO4LV
} 3lyQn"
_i.({s&_9
I@+lFG
public void setNSplitter(int nCount) ,$o-C&nC
{ _4~k3%w\`l
nSplitter = nCount; gnYnL8l`J
} NywB3
} j5'.P~
2;O c^
69?I?,7
/* Bac?'ypm
**Utility.java _RgxKp/d
*/ my=*zziN
package NetFox; ?!_u,sT
YlG;A\]k
E#8J+7
public class Utility { -uO%[/h;N
iczs8gj*
G|<]Ma9x
public Utility() _J+]SNk
{ EmYO5Whi
|c]> Q
$/MY,:*e
} T27:"LVw
GsR-#tV@
//线程睡眠 a\.//?
public static void sleep(int nSecond) @ 8A{ 9i
{ Hu[8HzJo
try{ WvIK=fdZ$
Thread.sleep(nSecond); x0y%\
} cvn-*Sj
catch(Exception e) (}VuiNY<3
{ U[blq M
e.printStackTrace (); @F>[DW]O
} `>dIF.
} qT 5WaO)
#}nBS-+
//日志 J!ln=h
public static void log(String sMsg) /IrKpmbq
{ L;L2j&i%v)
System.err.println(sMsg); 9Kq<\"7Bmz
} 2#,8evH
Y=PzN3
oM/B.U2a
public static void log(int sMsg) kOo>Iy
{ _a?wf!4>P
System.err.println(sMsg); Rc;1Sm9\
} ]v/t8`
} 39'X$!
7)g;Wd+H
"4J?JR
/* wOD/Z8
**TestMethod.java X%RQB$
*/ PEMxoe<+
package NetFox; g-4gI\
4;B=Qoxe
/5Gnb.zN)
public class TestMethod { 1uK)1%vK
=?y^O0v
NdaVT5RB
public TestMethod() _:oMyK'
{ ///xx/weblogic60b2_win.exe cL-6M^!a
try{ c%o5E%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E&}H\zt#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Ui]hA-:?y
SiteFileFetch fileFetch = new SiteFileFetch(bean); W66}\&5
fileFetch.start(); 9aW8wYL~b
} R4hav
catch(Exception e){e.printStackTrace ();} 7Y|Wy Oq
g)2m$#T&s
Lh8#I&x
} THegPD67J
s?1-$|*
NZC<m$')
public static void main(String[] args) U"jUMOMZ;
{ <m|FccvQ
new TestMethod(); Vs2v j
} krnvFZRTQ
} N^nDWK
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