社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 11629阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* <xz-7EqbwX  
**SiteFileFetch.java Z4sjH1W  
*/ \zDV|n~{w  
package NetFox; ZI]K+jza  
import java.io.*; pMrf i}esx  
import java.net.*; < VsZ$  
~/[N)RFD  
ds[~Cp   
public class SiteFileFetch extends Thread { A|nU _*  
-<.NEV  
#>NZN1  
SiteInfoBean siteInfoBean = null; //文件信息Bean 1S@k=EKM  
long[] nStartPos; //开始位置 (G'ddZAJV  
long[] nEndPos; //结束位置 ?E+XD'~  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ;!Bkk9r"H  
long nFileLength; //文件长度 5mBk[{  
boolean bFirst = true; //是否第一次取文件 CBHWMetJ*  
boolean bStop = false; //停止标志 @isqFKjph  
File tmpFile; //文件下载的临时信息 sTYl' Ieg  
DataOutputStream output; //输出到文件的输出流 1 SZa\ ][@  
5n#&Hjb*F0  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) GoXHVUyp  
public SiteFileFetch(SiteInfoBean bean) throws IOException Z)~4)71Y:  
{ D]_\i[x  
siteInfoBean = bean; {(Z1JoSl  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); EFOQ;q  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); @35]IxD  
if(tmpFile.exists ()) `/iN%ZKum  
{ 9LRY  
bFirst = false; |%9~W^b  
read_nPos(); [a6lE"yr  
} 3F3?be  
else B-zt(HG  
{ L1+cv;t  
nStartPos = new long[bean.getNSplitter()]; p gi7 JQ  
nEndPos = new long[bean.getNSplitter()]; OQyOv%g5C  
} GQ8P}McA  
ThB2U(Wf  
M](U"K?  
;W:Q}[  
} !%=k/|#  
RmCR"~   
Vt>E\{@[t  
public void run() ]t<%>Z$  
{ m 9Q{ )?J7  
//获得文件长度 CiF bk&-g  
//分割文件 Rh^$0Q*2  
//实例FileSplitterFetch O^ hV<+CX  
//启动FileSplitterFetch线程 ]e9kf$'  
//等待子线程返回 _E7eJSM.  
try{ @n3PCH6:Ao  
if(bFirst) }%|OnEk"  
{ Su~`jRN $  
nFileLength = getFileSize(); 3+ 'w%I  
if(nFileLength == -1) C<ljBz`,t  
{ -ybupUJcbv  
System.err.println("File Length is not known!"); Ja2.1v|r .  
} nwYeOa/t  
else if(nFileLength == -2) v4zARE9#  
{ wVB8PO8  
System.err.println("File is not access!"); b87d'# .  
} r e2%e-F"  
else a!.8^:B&  
{ XO>Y*7rO  
for(int i=0;i<nStartPos.length;i++) *QJ/DC$  
{ <z PyID`  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); qKXn=J/0tA  
} s,= ^V/c  
for(int i=0;i<nEndPos.length-1;i++) 7va%-&.&t  
{ fk_i~K  
nEndPos = nStartPos[i+1]; .l!Z=n|  
} ^ TS\x/P  
nEndPos[nEndPos.length-1] = nFileLength; hCrgN?M z  
} uq_SF.a'v  
} /:)4tIV  
*@Z'{V\  
Z9y:}:j"  
//启动子线程 {zcjTJ=Zt8  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; . j },  
for(int i=0;i<nStartPos.length;i++) hB4.tMgZ  
{ bBf+z7iyc  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |m% &Qb  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g}7B0 yo  
nStartPos,nEndPos,i); 0%GWc}o  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uB?YJf .T@  
fileSplitterFetch.start(); TnrMR1Zx  
} JP]K\nQx'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H+Wd#7l,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .0 K8h:I  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0 N(2[s_A  
nEndPos = " + nFileLength); -$r fu  
// fileSplitterFetch[nPos.length-1].start(); {_JLmyaerZ  
&+sN= J.x  
=G`m7!Q)  
//等待子线程结束 qi$8GX=~r  
//int count = 0; r_",E=e  
//是否结束while循环 ~*qGH  
boolean breakWhile = false; E*$:~w  
spf}{o  
,o`qB81  
while(!bStop) RL%{VE  
{ OkM>  
write_nPos(); -llujB%;,e  
Utility.sleep(500); ~Hq 2'  
breakWhile = true; l#Tm`br  
r]yq #T`z  
,^(T^ -  
for(int i=0;i<nStartPos.length;i++) 3y!CkJKv  
{ YY9q'x,w  
if(!fileSplitterFetch.bDownOver) TFhj]r^ {  
{ UTz;Sw?~hw  
breakWhile = false; U8d  wb  
break; S70ERRk  
} BsAglem  
} @UA>6F  
if(breakWhile) :5(TOF  
break; LLMkv!%D  
 Y+N87C<  
sr\MQ?\fB  
//count++; DmYm~hzJ  
//if(count>4) `i}\k  
// siteStop(); Mm5l>D'c  
} *VpQ("  
X*sF-T$.  
fAK  
System.err.println("文件下载结束!"); ?'%&2M zM  
} }5gQZ'ys'  
catch(Exception e){e.printStackTrace ();} )\e_I\-  
} 9/{g%40B^  
O =fT;&%.  
.'4*'i:  
//获得文件长度 TF'ssD  
public long getFileSize() 5]{YERa'  
{ C'Ymz`iQ  
int nFileLength = -1; ` :2C9,Xu  
try{ Vo\d&}Q  
URL url = new URL(siteInfoBean.getSSiteURL()); +$9w[ARN+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }K/[3X=B  
httpConnection.setRequestProperty("User-Agent","NetFox"); -vMP{,  
'K`)q6m  
#X)s=Y&5!T  
int responseCode=httpConnection.getResponseCode(); V3-LVgM%  
if(responseCode>=400) a'|0e]  
{ k;)L-ge9  
processErrorCode(responseCode); \l:n  
return -2; //-2 represent access is error f?]cW h%  
} )z aMycW  
Vq*p?cF .  
Ai/#C$MY$  
String sHeader; (GeJBw,Q  
NT/}}vES  
qAU]}Et/  
for(int i=1;;i++) f7`y*9^  
{ sU8D;ML7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \nLO.,  
//Utility.log(in.readLine()); \3KCZ  
sHeader=httpConnection.getHeaderFieldKey(i); `@ObM[0p(  
if(sHeader!=null) {>i'Pb0mG|  
{ v4&*iT  
if(sHeader.equals("Content-Length")) f; 22viE  
{ ~6OdPD  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NENbr$,G  
break; {\%x{  
} .VI2V-Q  
} Un<~P@T%  
else 'HC4Q{b`  
break; 4fN<pG,  
} jQc0_F\  
} ?O_;{(F_  
catch(IOException e){e.printStackTrace ();} H1X6f7`  
catch(Exception e){e.printStackTrace ();} Y-Z.AA,  
l-mUc1.S  
q3;HfZ  
Utility.log(nFileLength); V7&L+]!  
G~_dSa@g G  
u^`B#b '  
return nFileLength; # OJD<=")  
} \dP2xou=  
rsP1?Hxq  
zRz3ot,|  
//保存下载信息(文件指针位置) ci$o~b6V  
private void write_nPos() q H+~rj  
{ |ey6Czm  
try{ 7==Uoy*O  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4g6d6~098;  
output.writeInt(nStartPos.length); eX=W+&lj  
for(int i=0;i<nStartPos.length;i++) AttDD{Ta  
{ Q%85,L^U  
// output.writeLong(nPos); lwK Au!l  
output.writeLong(fileSplitterFetch.nStartPos); I|p(8 R!  
output.writeLong(fileSplitterFetch.nEndPos); nJ6bC^*)U  
} ^rx]Y;  
output.close(); UCl,sn  
} Q4UaqiL  
catch(IOException e){e.printStackTrace ();} O*30|[  
catch(Exception e){e.printStackTrace ();} N~a?0x  
} d9E:LZy  
YS;Q l\4   
nY6^DE2f  
//读取保存的下载信息(文件指针位置) g n'. 9";j  
private void read_nPos() 1(m8 9C[  
{ <%|2yPb]  
try{ ~*H!zKIx  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :HwB+Bjy  
int nCount = input.readInt(); 9XS'5AXN  
nStartPos = new long[nCount]; |n~- LH++  
nEndPos = new long[nCount]; pN?  
for(int i=0;i<nStartPos.length;i++) VG)kPKoi  
{ .aNy)Yu8  
nStartPos = input.readLong(); @k6>&PS  
nEndPos = input.readLong(); O)W1.]GMbf  
} dC)@v]#h  
input.close(); GUMO;rZs  
} ? -6oh~W<  
catch(IOException e){e.printStackTrace ();} mio\}S A  
catch(Exception e){e.printStackTrace ();} Ru2kC} Dx!  
} ;Lz96R@}  
@c5TSHSL.  
LA1UD+S  
private void processErrorCode(int nErrorCode) ^f@EDG8  
{ ^'#vUj:"  
System.err.println("Error Code : " + nErrorCode); @dw0oRF  
} O{Wy;7i  
kvKbl;<&#  
z`'{l {  
//停止文件下载 @'dtlY5;  
public void siteStop() I>:M1Yc0  
{ f~t*8rG~m  
bStop = true; WOquG  
for(int i=0;i<nStartPos.length;i++) RHeql*`  
fileSplitterFetch.splitterStop(); $O=m/l $  
^hLAMaR  
`O*+%/(  
} yyG:Kl  
} G 9d@vu  
//负责部分文件的抓取 E7ixl~  
**FileSplitterFetch.java U }xRvNz  
*/ tvavI9  
package NetFox; '`^`NI`  
iku) otUc  
aO6w :IO  
import java.io.*; {4\(HrGNk  
import java.net.*; .t$~>e .  
NZCPmst  
bfhap(F~(e  
public class FileSplitterFetch extends Thread { ~:v" TuuK  
n YWS'i@  
]|'Mf;  
String sURL; //File URL Qn6'E  
long nStartPos; //File Snippet Start Position i#=s_v8  
long nEndPos; //File Snippet End Position ?o?~Df&  
int nThreadID; //Thread's ID "1yXOy^2  
boolean bDownOver = false; //Downing is over Fn1|Wt*  
boolean bStop = false; //Stop identical 1r'skmxq  
FileAccessI fileAccessI = null; //File Access interface "'~55bG  
8 Zhx&  
>Ta|#]{  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {L4ta~2/T  
{ ]gx]7  
this.sURL = sURL; CM|?;PBuv  
this.nStartPos = nStart; c/%i,N\5  
this.nEndPos = nEnd; cba ~  
nThreadID = id; 6O>NDTd%  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -lAX-W 0  
} h`;w/+/Zr  
?%(:  
j&(aoGl@  
public void run() $GB/}$fd&  
{ AT+7!UGL  
while(nStartPos < nEndPos && !bStop) 3]$qY_|7  
{ .0}]/%al  
tUaDwIu#  
2= S;<J  
try{ Db3# ;  
URL url = new URL(sURL); <xv@us7  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3+ JkV\AF  
httpConnection.setRequestProperty("User-Agent","NetFox"); H$^IT#  
String sProperty = "bytes="+nStartPos+"-"; -T$%MX  
httpConnection.setRequestProperty("RANGE",sProperty); Xt& rYv  
Utility.log(sProperty); .?|pv}V  
^M_0M  
A 0~uv4MC  
InputStream input = httpConnection.getInputStream(); g ]%sX6T  
//logResponseHead(httpConnection); .EpcMXT%  
mO%F {'  
qy|[V   
byte[] b = new byte[1024]; FX}kH]  
int nRead; =Kqb V{!  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <#HQU<  
{ rY yB"|  
nStartPos += fileAccessI.write(b,0,nRead); Vz[tgb]-  
//if(nThreadID == 1) X+dLk(jI`u  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1g<jr.  
} -!4Mmp"2@u  
1<766  
h0ml#A`h  
Utility.log("Thread " + nThreadID + " is over!"); U|yXJ.Z3  
bDownOver = true; F`))qCgg]  
//nPos = fileAccessI.write (b,0,nRead); F8Y_L\q  
} dPvRbwH<  
catch(Exception e){e.printStackTrace ();} M5\$+Tu  
} 'ONCz  
} p`N+9t&I4  
fXD9w1  
>JVdL\3  
//打印回应的头信息 ~$w9L998+  
public void logResponseHead(HttpURLConnection con) zp.-=)D4e  
{ # O<,  
for(int i=1;;i++) ; D'6sd"  
{ >x'R7z23  
String header=con.getHeaderFieldKey(i); N5K\h}'%  
if(header!=null) Z8 eB5!$  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IPHZ~'M  
Utility.log(header+" : "+con.getHeaderField(header)); ,y5,+:Y ~  
else P-]u&m/6  
break; bSJ@ 5qS  
} ,#?iu?i/  
} [0>I6Jl  
Z/G`8|A  
7F$G.LhMw  
public void splitterStop() 2;2FyKF(  
{ h$`zuz  
bStop = true; 05SK$ Y<<  
} h[*:\P`  
F .h A.E  
v=8sj{g3,3  
} HAKB@h)  
[[FDt[ l4  
r&rip^40  
/* ?cur}`  
**FileAccess.java !a9`]c  
*//文件访问(定位,写) 4J5 RtK  
package NetFox; ?q{HS&k  
import java.io.*; 1buVV]*~  
\Dlmrke  
1Y+g^Z;G  
public class FileAccessI implements Serializable{ A  r,fmq  
0#y i5U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &) qs0  
RandomAccessFile oSavedFile; 6Cj$x.-K  
long nPos; nF1}?  
W#Eg\nT  
[%LIW%t|  
public FileAccessI() throws IOException 0&Z+P?Wb4  
{ a'!p^/6?  
this("",0); T"_f9?  
} 3q-Xj:FP  
BG/Q7s-?K  
SPu+t3  
public FileAccessI(String sName,long nPos) throws IOException eHE?#r16Z  
{ XP%/*am  
oSavedFile = new RandomAccessFile(sName,"rw"); (/$a*$  
this.nPos = nPos; Bcl6n@{2f  
oSavedFile.seek(nPos); ,hSTR)  
} :q34KP  
WJU[+|J  
JavSR1_  
public synchronized int write(byte[] b,int nStart,int nLen) N!lQ;o'  
{ Wj I NY  
int n = -1; s:zz 8oN  
try{ 5}Z_A?gy  
oSavedFile.write(b,nStart,nLen); 6<SX%Bc~  
n = nLen; 2 Q}^<^r  
} '5etZ!:  
catch(IOException e) 1fMl8[!JLu  
{ D}T+X ;u)K  
e.printStackTrace (); b|Sjh;  
} 3]rd!Gp=*  
S;tv4JY  
lvp8{]I<  
return n; >Q#\X=a>  
} zvOSQxGQ  
+ 'V ,z  
HDHC9E6  
} }cO}H2m  
,V &RpKek  
\Z8:^ct.P  
/* _Gtq]`y  
**SiteInfoBean.java UF PSQ  
*/ Z/oP?2/Afh  
package NetFox; vYNu=vnM  
|2!cPf^8  
*\#?)q  
public class SiteInfoBean {  WfH4*e  
f#3!Q!C^  
m {?uR.O  
private String sSiteURL; //Site's URL U2CCjAgRs  
private String sFilePath; //Saved File's Path yL #2|t(  
private String sFileName; //Saved File's Name kWZ/O  
private int nSplitter; //Count of Splited Downloading File i%# <Hi7  
dOFK;  
M/evZ?uis  
public SiteInfoBean() "JpnmE[`  
{//nSplitter的缺省值为5 9jf2b  
//default value of nSplitter is 5 NR.YeKsBq  
this("","","",5); q[ 5&  
} f9a_:]F  
><w=  
cz;gz4d8  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T:0#se  
{ F.$NYr/|y  
sSiteURL= sURL; }%Vx2Q  
sFilePath = sPath; RxUzJ  
sFileName = sName; Sp\ 7  
this.nSplitter = nSpiltter; {GhM,-%e  
d: LP8  
:<PwG]LO  
} [DSD[[ z[  
!g7bkA  
0oPcZ""X]  
public String getSSiteURL() ZU K'z  
{ )uazB!X  
return sSiteURL; )^]1j$N=3  
} Np2.X+  
l~'NqmXe  
cIOM}/gqv  
public void setSSiteURL(String value) Rd:wMy$  
{ L@x#:s=  
sSiteURL = value; &pN/+,0E  
} WmTg`[  
fl *>m,  
M D,+>kh  
public String getSFilePath() n]a/nv  
{ w6G<&1iH  
return sFilePath; |YWX.-aeo  
} ]vUTb9>{?  
cwBf((~  
J`[He$7)  
public void setSFilePath(String value) I3" GGp3L  
{ |P`:NAf2  
sFilePath = value; dZ{yNh.]  
} ,+o*>fD  
TW!>~|U)y  
%Kc2n9W  
public String getSFileName() {i|$^A3  
{ b$/ 'dnx  
return sFileName; ST25RJC  
} 0k 6S`e9gI  
>?)Df(n(9  
@DniYt/  
public void setSFileName(String value) FWl'='5L  
{ m8NKuhu  
sFileName = value; :uQ~?amM  
} MtXTh*4  
xy Pz_9  
C?fa-i0l^  
public int getNSplitter() xSL%1>MrN  
{ lbnH|;`$]m  
return nSplitter; G !;<#|a  
} {/K_NSg+h  
~[3B<^e  
m\;@~o'k  
public void setNSplitter(int nCount) vj4n=F,Z  
{ WN9K*Tt~o&  
nSplitter = nCount; C ]+J  
} | x/Z qY  
} ylPDM7Ka  
THf*<|  
\%$z!]S>  
/* 6rg?0\A<  
**Utility.java KQ2jeJ/pj  
*/ \K%A}gnHe  
package NetFox; JVt(!%K}&  
n Wb0S  
qgk6 \&K[  
public class Utility { %eQw\o,a  
`AcT}. u  
W=ar&O~}n  
public Utility() ;=F]{w]$+  
{ VtzX I2.2  
4pC.mRu 0  
>Z&Y!w'A|u  
} *\T ]Z&E"  
FCPi U3  
//线程睡眠 (|_N2R!  
public static void sleep(int nSecond) ' Y cVFi  
{ $*z>t*{7  
try{ #t?tt,nc}  
Thread.sleep(nSecond); j/PNi@  
} iw?*Wp25  
catch(Exception e) 3lT>C'qq  
{ XXA1%Lw%  
e.printStackTrace (); cr"AK"TQ  
}  g1B[RSWv  
} '/ v@q]!  
@WfX{485  
//日志 1GI/gc\  
public static void log(String sMsg)  k.("<)  
{ *9I/h~I  
System.err.println(sMsg); <{k r5<  
} kZJ.G  
)ND%MYJSq  
g}Esj"7  
public static void log(int sMsg) P8=!/L2?  
{ r'~^BLT`#  
System.err.println(sMsg); ExJexjOWI^  
} T~JE.Y3B3  
} 1@vlbgLr@  
/`vn/X^?^  
F3pBk)>a\  
/* ">hOD'PG  
**TestMethod.java b%"Lwqdr7  
*/ TX7]$Wj  
package NetFox; M->$ 'Zgh`  
AV:P/M^B  
5\\a49k.p  
public class TestMethod { R1lC_G]  
YNV4'  
LH]<+Zren  
public TestMethod() iw)^; 8q  
{ ///xx/weblogic60b2_win.exe }vspjplk^  
try{ %jnSJjcq  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i |IG  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @$ggPrs  
SiteFileFetch fileFetch = new SiteFileFetch(bean); AHl1{* [  
fileFetch.start(); LCf)b>C*  
} Z[pMlg6Z  
catch(Exception e){e.printStackTrace ();} /Xo8 kC  
N6wCCXd  
]> 36{k]&  
} ic]b"ItD  
0}d^UGD  
>Qg 9KGk'  
public static void main(String[] args) W]U}, g8Z  
{ @Wb_Sz4`  
new TestMethod(); 2qkZ B0[  
} o2 vBY]Tj  
} Fy8$'oc  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五