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)); GrM~%ng
} #Q'i/|g
for(int i=0;i<nEndPos.length-1;i++) B]*&lRR
{ gmLw.|-
nEndPos = nStartPos[i+1]; \Z+v\5nmO
} }ZYK3F
nEndPos[nEndPos.length-1] = nFileLength; <wE2ly&x
} $S,Uoh
} 6_XX[.%
T7W+K7kbI
*ac#wEd
//启动子线程 ppV\FQ{K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xVl90ak
for(int i=0;i<nStartPos.length;i++) cz T@txF
{ dk(-yv'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }U^9(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [MiD%FfcNH
nStartPos,nEndPos,i); ZgXh[UHQy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,E>VYkoA
fileSplitterFetch.start(); G^2"\4R]p
} zG@!(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G&uj}rj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PTePSj1N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *=2jteG=3.
nEndPos = " + nFileLength); W_DO8nX
// fileSplitterFetch[nPos.length-1].start(); x_@ev-
fmSw%r|pT
\C<rg|
//等待子线程结束 }`_2fJ6
//int count = 0; "lz!'~im
//是否结束while循环 e.HN%LrhS
boolean breakWhile = false; |f>y"T+1
9*2hBNp+
!Uj !Oy
while(!bStop) +Nza@B d
{ cnIy*!cJs
write_nPos(); yRgo1ow]
Utility.sleep(500); Gf%o|kX]
breakWhile = true; 9J|YP}%
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Gg;#U`
for(int i=0;i<nStartPos.length;i++) KBJ|P^W5j
{ P' J_:\
if(!fileSplitterFetch.bDownOver) n `n3[
{ 3p^WTQ>(
breakWhile = false; d&ZwVF!
break; 4\$Ze0tv
} /60[T@Mz
} ;^*^ :L
if(breakWhile) 6*LU+U=`
break; #!hpe^t
}j:ae \(
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//count++; 2 G"p:iPp
//if(count>4) m+u>%Ys`
// siteStop(); Tbwq_3fK
} Vm.u3KE
]{"(l(
8n73MF
System.err.println("文件下载结束！"); z$<6;2
} {?jdPh
catch(Exception e){e.printStackTrace ();} Zq`bd55~
} 6?a(@<k_
(Dn-vY'
.(hb8 rCM
//获得文件长度 -e)bq:T
public long getFileSize() nRo`O
{ e;pNB
int nFileLength = -1; lGM3?AN
try{ BT#>b@Xub
URL url = new URL(siteInfoBean.getSSiteURL()); pUwX cy<n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j)]'kg
httpConnection.setRequestProperty("User-Agent","NetFox"); I;|Aiu*
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int responseCode=httpConnection.getResponseCode(); ^twv0>vEo
if(responseCode>=400) 3@&H)fdp6a
{ pts}?
processErrorCode(responseCode); cp2fDn
return -2; //-2 represent access is error d,[KcX
} wYxizNv,
R utW{wh
.kYzB.3@]
String sHeader; ?ykZY0{B
,-1$Vh@wM
GS$k
for(int i=1;;i++) w|Mj8Lc+
{ i&30n#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1Efl|lV
//Utility.log(in.readLine()); "p;DQ-V
sHeader=httpConnection.getHeaderFieldKey(i); !'gz&3B~h
if(sHeader!=null) "''<:K|
{ m0* B[
if(sHeader.equals("Content-Length")) Pz)QOrrG~
{ 87Uv+((H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nn
break; x2B"%3th0
} X@Bpjg
} -#o+x Jj
else $oQsh|sTI
break; 6P~"7k
} hHg gH4T
} &59#$LyH`%
catch(IOException e){e.printStackTrace ();} 6^aYW#O<Ua
catch(Exception e){e.printStackTrace ();} b mm@oi
6m" 75
_9@?Th&_e
Utility.log(nFileLength); qN0#=X
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I>3]4mI*a
return nFileLength; 4GfLS.Ip
} ygW@[^g
'f}S,i +q
]p*) PpIl
//保存下载信息（文件指针位置） vedMzef[@>
private void write_nPos() _Ry.Wth
{ _%2Umy|
try{ pzax~Vp
output = new DataOutputStream(new FileOutputStream(tmpFile)); tZYI{m{
output.writeInt(nStartPos.length); 0V#t ;`Q3
for(int i=0;i<nStartPos.length;i++) )[)]@e
{ Yz,!#ob$
// output.writeLong(nPos); G}-.xj]
output.writeLong(fileSplitterFetch.nStartPos); 4d 3Znpf
output.writeLong(fileSplitterFetch.nEndPos); &v-V_.0(H
} 5>@uEebkv]
output.close(); L@4zuzmlb
} LA?\~rh!
catch(IOException e){e.printStackTrace ();} Z :9VxZ
catch(Exception e){e.printStackTrace ();} %1@<),
} lp}WBd+
^'fKey`
`I>K?
//读取保存的下载信息（文件指针位置） ; BZM~'
private void read_nPos() ;a3nH
{ XeSbA
try{ #VV.[N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Doh|G:P]#
int nCount = input.readInt(); e87- B1`
nStartPos = new long[nCount]; Y+ Z9IiS7
nEndPos = new long[nCount]; $ tNhwF
for(int i=0;i<nStartPos.length;i++) "k<:a2R
{ M&ij[%i
nStartPos = input.readLong(); ]jb4Z
nEndPos = input.readLong(); k2uiu
} |{PJT#W%
input.close(); 8-"5|pNc
} ij i.3-
catch(IOException e){e.printStackTrace ();} &&}5>kg>d
catch(Exception e){e.printStackTrace ();} {&#~t4
} D'`"_
qZJ*J+
ow_y
private void processErrorCode(int nErrorCode) kNj3!u$
{ V"H7zx
System.err.println("Error Code : " + nErrorCode); Jo3(bl%u
} unnx#e]
V*zz- 2_i
klJ[ {p
//停止文件下载 F!&pENQ
public void siteStop() ~{vdP=/WP
{ MgQU6O<
bStop = true; "-n%874IT
for(int i=0;i<nStartPos.length;i++) 3> #mO}\
fileSplitterFetch.splitterStop(); 5; PXF
$XQxWH|
eqZ+no
} -+rF]|Wi
} !Gp3/<"Wy$
//负责部分文件的抓取 _`_IUuj$E
**FileSplitterFetch.java !e'0jf-~
*/ 7vaN&%;E%
package NetFox; NceB'YG|
p$nK@t}
fHd!/%iG
import java.io.*; {* j^g6;
import java.net.*; [u9JL3
!049K!rP{
`SjD/vNE
public class FileSplitterFetch extends Thread { ~BvY8\@B
BO4 K#H7
9J7J/]7f
String sURL; //File URL uUz`=4%A
long nStartPos; //File Snippet Start Position ! F <] T
long nEndPos; //File Snippet End Position 8F^,8kIR
int nThreadID; //Thread's ID RF5q5<0
boolean bDownOver = false; //Downing is over |R;l5ZKvV
boolean bStop = false; //Stop identical +F o$o
FileAccessI fileAccessI = null; //File Access interface em1cc,
%L j0
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k9)u3
{ i6md fp|k
this.sURL = sURL; 5Y Q
this.nStartPos = nStart; 1_NG+H]x9
this.nEndPos = nEnd; Z|(c(H2
nThreadID = id; eky(;%Sz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,xYsH+ybA
} 'xbERu(Y
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+lW}ixt
public void run() *NW QmC~
{ z,bX.*.-
while(nStartPos < nEndPos && !bStop) @?Gw|bP
{ l+2cj?X
o8'Mks
V5O=iMP
try{ xegQRc
URL url = new URL(sURL); I/HV;g:#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K3rBl!7v
httpConnection.setRequestProperty("User-Agent","NetFox"); ~`2&'8
String sProperty = "bytes="+nStartPos+"-"; u`Z0{d
httpConnection.setRequestProperty("RANGE",sProperty); zr.+'
Utility.log(sProperty); .%?-As
Ug7`ez4vw
`z}vONXpAX
InputStream input = httpConnection.getInputStream(); !ww:O|0
//logResponseHead(httpConnection); j/H>0^
c6,s+^^
i_=?eUq%q/
byte[] b = new byte[1024]; F#1 Kk#t
int nRead; a|QE *s.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xHJ8?bDp
{ Q1`<fD
nStartPos += fileAccessI.write(b,0,nRead); 6F*-qb3
//if(nThreadID == 1) rFmKmV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /5Zp-Pq
} ]<kupaRQ
S jVsF1d_
id;#{O$
Utility.log("Thread " + nThreadID + " is over!"); b96t0w!cs
bDownOver = true; 7uPZuXHxcu
//nPos = fileAccessI.write (b,0,nRead); r$GPYyHK
} l'*^$qc
catch(Exception e){e.printStackTrace ();} /l,+oG%\
} ?P""KVpo
} XM6".eF)M
<NG/i i=
x&C%4Y_]
//打印回应的头信息 6<x~Mk'u)
public void logResponseHead(HttpURLConnection con) Xhcn]
{ 4$ Dt8!p0
for(int i=1;;i++) YV/>8*i
{ v7i^O`{eD?
String header=con.getHeaderFieldKey(i); d,c8Hs8
if(header!=null) K8HIuQ!=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D|@bGN
Utility.log(header+" : "+con.getHeaderField(header)); gq'>6vOj
else b?_e+:\UV
break; I|,pE**T
} Y5dD|]F|
} ]} 61vV
q$r&4s)To
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public void splitterStop() z Yw;q3"
{ U;xu/xDRi
bStop = true; Y^52~[w~
} #`W=mN(+k
S6v!GQ
U|gpCy
} {<qF}i:V
.L9']zXc`
I2f?xJ2/Z
/* ~xGoJrF\
**FileAccess.java 1T ( u
*//文件访问(定位，写) Kv(z4z
package NetFox; *~p(GC
import java.io.*; !^m%O0DT
B:4Ka]{YO
&&=[Ivv
public class FileAccessI implements Serializable{ qG<7hr@x]
t\h$&[[l'z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Sw~(uH_l
RandomAccessFile oSavedFile; ^ eQFg>
long nPos; '77~{jy
-?s&pKi
NXpmT4
public FileAccessI() throws IOException 2{bhA5L
{ bS.s?a
this("",0); 33Jd!orXU
} JVtQ,oZ
=#qZ3 Qz_
L!t@-5~
public FileAccessI(String sName,long nPos) throws IOException C5xag#Z1
{ xJ{_qP
oSavedFile = new RandomAccessFile(sName,"rw"); vY6oVjM
this.nPos = nPos; XZ`:wmc|
oSavedFile.seek(nPos); oM!xz1kVL
} :.kZR;
07V8;A<,
,7W:fwdR
public synchronized int write(byte[] b,int nStart,int nLen) {( #zcK
{ _AFQ>j
int n = -1; 62)d22
try{ NzQ9Z1Mxy
oSavedFile.write(b,nStart,nLen); : [q0S@
n = nLen; 'OwyyPBF
} #B8*gFZB
catch(IOException e) A /(lKq
{ Z$p0&~
e.printStackTrace (); ,apNwkY
} `K*b?:0lp
B z^|SkEit
q2hFOm
return n; ';0 qj$#
} ]1D%zKY%$Z
-(i(02PX
G O{.9_2
} *wuqa)q2
r> k-KdS
"g>.{E5
/* )"Q*G/+2Ie
**SiteInfoBean.java ]PWDE"
*/ {ox2Tg?
package NetFox; M*sR3SZ
mMSh2B
+vW)vS[
public class SiteInfoBean { :w`3cwQ
l.`u5D
.~>?*}
private String sSiteURL; //Site's URL j~E",7Q'
private String sFilePath; //Saved File's Path K<4Kk3
private String sFileName; //Saved File's Name }lP;U$
private int nSplitter; //Count of Splited Downloading File ljC(L/I
eSEq{?>
FdzNE
public SiteInfoBean() ST5V!jz
{//nSplitter的缺省值为5 -#In;~
//default value of nSplitter is 5 QzOkpewf
this("","","",5); mj&57D\fq
} 0p(L'
,HB2hHD
.pPm~2]z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R!(ZMRMn
{ >(r{7Qg
sSiteURL= sURL; sa1h%<
sFilePath = sPath; {D`'0Z1"
sFileName = sName; ~1 ~Xfo>
this.nSplitter = nSpiltter; Z(u5$<up
~YP Jez
X(A.X:"
} S0d~.ah30
d>0+A)6>
2 PqS%`XiS
public String getSSiteURL() G(iJi
{ q[3x2sR
return sSiteURL; i;z{zVR
} ^T5X)Nu{=C
h6_(?|:-(
69m ;XdkKz
public void setSSiteURL(String value) s 5WqR8
{ JL=U,Mr6
sSiteURL = value; H 3@Z.D
} {ZU1x C
.zg8i_
\OILWQ[/
public String getSFilePath() oF]cTAqhC.
{ [AU II*:}
return sFilePath; `B/0iA
} i;/xK=L
>Dw~POMy
^3VR-u<O
public void setSFilePath(String value) );V2?G`/
{ oA] KE"T
sFilePath = value; $ _j[2EU
} h4|i%,f
NLS"eDm
x5}'7,A
public String getSFileName() 1MlUG5
{ bmgncwlz
return sFileName; +mj*o(
} ^I8Esl8
Fm\"{)V:b
in+}/mwfC
public void setSFileName(String value) x8Loyt_C
{ {S/yL[S.
sFileName = value; KWAb-yB
} 7ELMd{CD
C%d_@*82
`Z:R Ce^
public int getNSplitter() 3@+b}9s8
{ hu_ ^OlF
return nSplitter; }%b;vzkG5
} 7SDFz}
PyVC}dUAX
o#) {1<0vg
public void setNSplitter(int nCount) !+>v[(OzM
{ qm/Q65>E
nSplitter = nCount; :NJ_n6E
} pl@O N"=[
} ,B?~-2cCz
OsBo+fwT
<,o>Wx*1C
/* Z;9>S=w!
**Utility.java ^b:(jI*l
*/ .2d9?p3Y
package NetFox; :w}{$v}#D;
T134ZXqqz
V7#v6!7A@
public class Utility { mxor1P#|
!It`+0S b
%CWPbk^
public Utility() D\IjyZ-O
{ SJD@&m%?[
9T#;,{VQ
P96pm6H_;
} _zlqtO
zvABU+{jD
//线程睡眠 fYKOJ5f
public static void sleep(int nSecond) C{TA.\
{ .MO\uh0N
try{ " \I4u{zC
Thread.sleep(nSecond); "KcA
} c/c$D;T
catch(Exception e) <: &*
{ a]Lp?
e.printStackTrace (); ga?*DI8w
} zdXkR]
} $kR N h6
OL4z%mDZi
//日志 Y5fLmPza
public static void log(String sMsg) {U&.D [{&
{ 74!oe u.>
System.err.println(sMsg); !9 fz(9
} :W b j\
Ol4+_n8xj
>S$Z
public static void log(int sMsg) Uj&W<'I
{ xsWur(>]
System.err.println(sMsg); WJI[9@^I~
} v<Bynd-
} ECv)v
l5L.5$N
E=){K
/* <uj8lctmP
**TestMethod.java pp9Zb.D\
*/ mPq$?gdp
package NetFox; wAnb Di{W
!w&kyW?e
2^?:&1:
public class TestMethod { apE
n3J53| %v
cwGbSW$t
public TestMethod() t&?im<
{ ///xx/weblogic60b2_win.exe ^>"z@$|\:
try{ qzb<J=FAU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R8.CC1Ix
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K~ ;45Z2
SiteFileFetch fileFetch = new SiteFileFetch(bean); '\jd#Kn'h
fileFetch.start(); (b`]M`Fc
} Nk {XdrY
catch(Exception e){e.printStackTrace ();} V!)O6?l
\QmCeB
IIy~[4dW
} ~'R(2[L!;
$s<Ne{?
McPNB`.H
public static void main(String[] args) y8fsveX
{ ;5@ t[r
new TestMethod(); xe/(
} {rcnM7 S1L
} =y=cW1TG
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