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)); =<aFkBX-
} u=~`5vA
for(int i=0;i<nEndPos.length-1;i++) E1Q#@*rX>
{ })uyq_nz
nEndPos = nStartPos[i+1]; t&5Ne ?
} ?-`&YfF
nEndPos[nEndPos.length-1] = nFileLength; OQ<;w
} ze5#6Vzd&
} 0/7.RpX,.
u`(yT<>H
$*_79F2zN
//启动子线程 Ks(l :oUB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gy|o#&e]%
for(int i=0;i<nStartPos.length;i++) s)-bOZi
{ ".( G,TW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &><b/,]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), upeioC q
nStartPos,nEndPos,i); .s41Tc5u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $X\2h+ Os
fileSplitterFetch.start(); @/$i -?E
} !>Q\Y`a,*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^vxNS[C`;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ? }`mQ<~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ==%5Ci7qMy
nEndPos = " + nFileLength); e8(Qx3T?b
// fileSplitterFetch[nPos.length-1].start(); 8o $` '
6jm/y@|F!
u%"5<ll
//等待子线程结束 ;Kg7}4`I
//int count = 0; D97 vfC
//是否结束while循环 >X"\+7bw
boolean breakWhile = false; uocFOlU0n
)g3c-W=
SsfC m C
while(!bStop) CMv8n@ry
{ V;J3lV<
write_nPos(); /"~UGn]R
Utility.sleep(500); Q:y'G9b
breakWhile = true; =9p3^:S
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pbWjTI$
for(int i=0;i<nStartPos.length;i++) c_.Fe'E
{ i?eVi
if(!fileSplitterFetch.bDownOver) :+ 1Wmg
{ $ZB`4!JxG
breakWhile = false; Qr6PkHU
break; M&9urOa`
} Au(oKs<
} wPcEvGBN=
if(breakWhile) cb{"1z
break; \,v+ejhw
QJjk#*?,|
TK~KM
//count++; @" umY-1f
//if(count>4) u'DpZ
// siteStop(); 8=0I4\
} $2}%3{<j
EUV8H}d5
a=9QwEZ
System.err.println("文件下载结束！"); oQo5y_o~
} &Ll&A@yU
catch(Exception e){e.printStackTrace ();} p_EM/jI,
} Wfc~"GQq4
uNw9g<g:V[
0B}2~}#
//获得文件长度 0O]v|
public long getFileSize() j}(m$j'
{ "oF)u1_?
int nFileLength = -1; G!%8DX5
try{ J^<uo(
URL url = new URL(siteInfoBean.getSSiteURL()); :l iDoGDi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &rX#A@=
httpConnection.setRequestProperty("User-Agent","NetFox"); C[#C/@
[9MbNJt 8~
3Z#WAhfS:
int responseCode=httpConnection.getResponseCode(); ^7=7V0>,:
if(responseCode>=400) '^$+G0jv
{ \.Op6ECV9
processErrorCode(responseCode); "{t]~urLd
return -2; //-2 represent access is error x5/&,&m`%
} /s=veiH
p7r/`_'|
tp&|*M3
String sHeader; cKoW5e|u
@tD (<*f+
5nsoWqnE8
for(int i=1;;i++) >&7^yXS
{ kl9~obX 1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _./s[{ek
//Utility.log(in.readLine()); `c-omNu
sHeader=httpConnection.getHeaderFieldKey(i); 'ShK7j$
if(sHeader!=null) 6Q_A-X3hk
{ ev_'.t'
if(sHeader.equals("Content-Length")) /5j5\F:33
{ R*S:/s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y#=MN~##t
break; T5.^ w
} >V]9<*c
} ,j.bdlI#
else Cz9MXb]B
break; 3hUP>F8
} JAXD\StC
} DGS,iRLnA
catch(IOException e){e.printStackTrace ();} AS;qJ)JfzQ
catch(Exception e){e.printStackTrace ();} |')PQ
Aq3\Q>klH)
&Vgpv#&Cfx
Utility.log(nFileLength); wp> z04
@>V;guJC%
*vvm8ik
return nFileLength; 1)zXv
} =]/<Kd}A.
MOnTp8
mo(>SnS<
//保存下载信息（文件指针位置） ~<s =yjTu+
private void write_nPos() oDi+\0
{ Qh-:P`CN
try{ n&?)gKL0g
output = new DataOutputStream(new FileOutputStream(tmpFile)); Dh?I
output.writeInt(nStartPos.length); M'|p<SO]
for(int i=0;i<nStartPos.length;i++) 4i^WE;|s
{ \4C[<Gbx$(
// output.writeLong(nPos); u|.7w2
output.writeLong(fileSplitterFetch.nStartPos); Ek6g?rj_
output.writeLong(fileSplitterFetch.nEndPos); c/v|e&q
} xk7Dx}
output.close(); *kYGXT,f]
} :Q@/F;Z?
catch(IOException e){e.printStackTrace ();} -V[x q
catch(Exception e){e.printStackTrace ();} VfP\)Rl
} AYNdV(
|5X[/Q*K`W
[;sTl~gC
//读取保存的下载信息（文件指针位置） =adHP|S
private void read_nPos() IAq o(Qm
{ 0_MtmmL.
try{ d%-/U!z?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W g6H~x
int nCount = input.readInt(); iemp%~UZ
nStartPos = new long[nCount]; $gD8[NAIx=
nEndPos = new long[nCount]; SPt/$uYJ
for(int i=0;i<nStartPos.length;i++) |g!d[ct]
{ ^m&P0
nStartPos = input.readLong(); u#Jr_ze
nEndPos = input.readLong(); @h!Z0}dX(
} ,c{ckm
input.close(); i.`n^R;N
} 150-'Q
catch(IOException e){e.printStackTrace ();} NVsaV;u
catch(Exception e){e.printStackTrace ();} ~T-uk
} ar}-~~h 5
7Zdg314
-57~7 <N
private void processErrorCode(int nErrorCode) ()O&O+R|)
{ \]5I atli
System.err.println("Error Code : " + nErrorCode); /sT?p=[.
} ubOXEkZ8N
2{vAs
ZILJXX4
//停止文件下载 "*F`,I3
public void siteStop() ~QxW^DGa7]
{ B%MdJD>
bStop = true; pq&[cA_w
for(int i=0;i<nStartPos.length;i++) c1jRj=\
fileSplitterFetch.splitterStop(); g,]m8%GHE
J@6j^U
-C3[:g
} 6l;2kztGp
} )`R}@(r.
//负责部分文件的抓取 %!(C?k!\
**FileSplitterFetch.java Y68A+ B.
*/ qIsf!1I?
package NetFox; dpylJ2
3Ke6lV)uq
m|{^T/kIbQ
import java.io.*; 7*KUM6z
import java.net.*; =r7!QXPH}
6kdbbGO-
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public class FileSplitterFetch extends Thread { "NGfT:HV
]7Sf)
L/C~l3
String sURL; //File URL AD?XJ3
long nStartPos; //File Snippet Start Position !U m9ceK
long nEndPos; //File Snippet End Position vIOGDI>
int nThreadID; //Thread's ID K.Y`/<
boolean bDownOver = false; //Downing is over G:tY1'5
boolean bStop = false; //Stop identical P~=yTW
FileAccessI fileAccessI = null; //File Access interface |vl~B|",
OoH-E.lp
sVw:d_ E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .O5V;&,
{ m:[I$b6AY
this.sURL = sURL; Q[rZ1z
this.nStartPos = nStart; UF#!6"C@
this.nEndPos = nEnd; AguE)I&m
nThreadID = id; /[\g8U{5B}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yxp,)os:
} :;]9,n
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~i>DF`w$
public void run() %\T,=9tD\
{ 3-{BXht)
while(nStartPos < nEndPos && !bStop) 3c3;8h$k
{ _ s3d$C?B
b&&l
kexV~Q
try{ e7xBi!I)~
URL url = new URL(sURL); Xi[]8o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n>j2$m1[
httpConnection.setRequestProperty("User-Agent","NetFox"); :e;6oC*"q
String sProperty = "bytes="+nStartPos+"-"; DlE,aYB
httpConnection.setRequestProperty("RANGE",sProperty); j7kX"nz
Utility.log(sProperty); kF~(B]W(
V@k+RniEO
.G!xcQ`?
InputStream input = httpConnection.getInputStream(); =zK4jiM1
//logResponseHead(httpConnection); 4hwb] Yz
J#F5by%8
b2UDPW
byte[] b = new byte[1024]; YxJQ^D`
int nRead; g}D)MlXRq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nco.j:
{ NOXP}M
nStartPos += fileAccessI.write(b,0,nRead); lsOv#X-bE
//if(nThreadID == 1) 9>S)*lU&s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :!oJmvy
} 208^Yu
jo<xrn\
HC6U_d1-6
Utility.log("Thread " + nThreadID + " is over!"); C:t>u..
bDownOver = true; #[{{&sN
//nPos = fileAccessI.write (b,0,nRead); &3Zb?
} rBTg"^jsw
catch(Exception e){e.printStackTrace ();} X_o#!
} =IsmPQKi
} xBTx`+%WS
D`a6D
B\c_GXUw
//打印回应的头信息 )0exGx+:
public void logResponseHead(HttpURLConnection con) HdqB B
{ Bc"MOSV0
for(int i=1;;i++) Yjc U2S"=P
{ 7b>_vtrt
String header=con.getHeaderFieldKey(i); [:cD
if(header!=null) ;kk[x8$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zY_J7,0g
Utility.log(header+" : "+con.getHeaderField(header)); G^k'sgy.
else 5+M,X kg
break; Qq`S=:}~x
} rz%~=Ca2j
} :C} I6v=
qS/}aDk&
j*?8w(!
public void splitterStop() Jq&Hz$L|
{ ,Zn6T"[$
bStop = true; {kk%_q
} //2O#Fg{/
?pW1}:z
uS`}
} O>]i?
BJux5Nh
r{R<J?Y
/* );d07\V
**FileAccess.java .t1:;H b
*//文件访问(定位，写) w{*kbGB8s7
package NetFox; KSchgon0V
import java.io.*; qKfUm:7Q_
eavn.I8J
H_RfIX)X
public class FileAccessI implements Serializable{ iN Oj@3x
%(W&(eN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8)1q,[:M
RandomAccessFile oSavedFile; {k3ItGQ_
long nPos; =m2_:&@0x
W:RjWn@<
2~$S @c
public FileAccessI() throws IOException :lB`K>)iB}
{ j J{F0o
this("",0); LRu,_2"
} r89AX{:
/&Oo)OB;
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public FileAccessI(String sName,long nPos) throws IOException F}u'A,Hc
{ >SDQ@63E?
oSavedFile = new RandomAccessFile(sName,"rw"); (Ut8pa+yX
this.nPos = nPos; 'M~`IN`
oSavedFile.seek(nPos); QGuqV8 y0
} ~6t!)QATnp
$vu*# .w
-n9&W
public synchronized int write(byte[] b,int nStart,int nLen) ^\ x'4!W
{ fY&TI}Y
int n = -1; #!F>cez
try{ xA Ez1
oSavedFile.write(b,nStart,nLen); bHG<B
n = nLen; v-z%3x.f
} Ih:Q}V#6
catch(IOException e) dzOco)y
{ kku<0<(N
e.printStackTrace (); JI.=y5I
} _s5^\~ao
H}kZ;8
[ *Dj:A)V^
return n; C~pas~
} %cSx`^`6j
~Q_7HJ=^$
X3}eq|r9
} cOV9g)7^O
M)oKtiav*
5FR#CQ
/* x9Z89Gwi
**SiteInfoBean.java XZKlE F?
*/ {nwoJ'-V
package NetFox; {jO+N+Ez9
F `o9GLxM}
s<{ Hu0K$
public class SiteInfoBean { V gMgeja
]_h3
j2Dw7"f3
private String sSiteURL; //Site's URL z+yq%O
private String sFilePath; //Saved File's Path kZG.Id
private String sFileName; //Saved File's Name d MR?pbD
private int nSplitter; //Count of Splited Downloading File v`,!wS
OlCqv-B2&
"HJ^>%ia
public SiteInfoBean() x\G%
{//nSplitter的缺省值为5 v%qOW)].
//default value of nSplitter is 5 ! eZls
this("","","",5); wU+r]SK@
} 7G_<+rn
J| N 6r
<{cY2cx~3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CImp,k0
{ xw9ZRu<z
sSiteURL= sURL; F~6]II
sFilePath = sPath; ,5$G0
sFileName = sName; Fy{yg]O"
this.nSplitter = nSpiltter; ;<garDf
R278^E
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} [<53_2]~
Eto"B"
YAc:QVT87
public String getSSiteURL() <ZSXOh,'
{ `w 6Qsah
return sSiteURL; jcqUY+T$
} M]PZwW8
`TJhH<z"%
^nPy(Q0
public void setSSiteURL(String value) O(W"QY
{ /.0K#J:
sSiteURL = value; mzK0$y#*o
} D-/6RVq0m
!-}Q{<2@W
I9Ohz!RQ
public String getSFilePath() IVh5SS
{ `;}`>!8j
return sFilePath; <5E'`T
} ch8VJ^%Ra1
4uiq'-
i6V$mhL
public void setSFilePath(String value) 6#U~>r/
{ rQ*w3F?:
sFilePath = value; iXm&\.%
} ~k&b
I4N7wnBp
zU!{_Ao9
public String getSFileName() J`5+Zngr
{ ura&9~
return sFileName; p"hO6b%V
} 0;TiNrzg
x4v:67_^
&)k=ccm
public void setSFileName(String value) 73X*|g[O
{ ^}~Q(ji7
sFileName = value; hOB<6Tm[
} |/K|Vwa
Trs~KcsD
E'\gd7t ;
public int getNSplitter() *}89.kCBF
{ y7UU'k`
return nSplitter; xH2'PEjFM
} r7W.}n*
R7Qj<,
~}b0zL
public void setNSplitter(int nCount) n3$=&
{ Q$U.vF7BnP
nSplitter = nCount; }BM`4/
} VvW4!1Dl
} \YzKEYx+
: 2%eh
c-hc.i}!
/* YWn""8p;P
**Utility.java R_G2C@y*
*/ UUfM7gq
package NetFox; 4|_xz;i
:? B4q#]N
*N$XQ{o
public class Utility { u;9iuc`*
c{Z "'t7
0\!Bh^++1
public Utility() i{EQjZ
{ ="]r{
.<QKQ%-
sd\}M{U
} 3Y#
c<_1o!68
//线程睡眠 h i!K-_Uy
public static void sleep(int nSecond) |I1,9ex
{ kKF=%J?X
try{ /b #w.>e
Thread.sleep(nSecond); kI`HD
} I7Kgi3
catch(Exception e) -I{op wd
{ JYNnzgd
e.printStackTrace (); Y&bYaq
} gWHY7rv
} =T3{!\tH
?x",VA
//日志 BywEoS
public static void log(String sMsg) G h+;Vrx
{ ?M4ig_
System.err.println(sMsg); UZt3Ua&J
} sRT5i9TQ
WY|~E%k
CX/[L)|Ru
public static void log(int sMsg) b(N+_= n
{ ;sA 5&a>!
System.err.println(sMsg); Bs0~P 4^
} i +@avoW
} 4}D&=0IZ
w;@v#<q6
by9UwM=gp
/* g.Ur~5r
**TestMethod.java G0:<#?<5
*/ w@2NXcmw
package NetFox; w +UBXW
DA=LR
ww %c+O/
public class TestMethod { DOtz
H$?MPA-c
W:<2" &7
public TestMethod() ~L&z?'V
{ ///xx/weblogic60b2_win.exe |goBIp[
try{ Ow?~+) 4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a?Fz&BE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1y[~xxgE
SiteFileFetch fileFetch = new SiteFileFetch(bean); R|Bi%q|4P
fileFetch.start(); t@lTA>;U@
} " AvEo
catch(Exception e){e.printStackTrace ();} i8Be%y%y
A*qR<cp[
`vt+VUNf
} r9}(FL/)b
(~\HizSl
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public static void main(String[] args) xs6!NY
{ -d!84_d9
new TestMethod(); 6@0?~
} N*m;A6?
} Jyd[Sc)
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